- Mercedes-Benz A-Class AMG Sport, 2013
Mercedes-Benz has started completely afresh for the third generation of its compact front-wheel drive A-Class. The latest Mercedes-Benz A-Class is based on all-new vehicle architecture and assembly techniques and introduces sportier and more dynamic design with greater emotional appeal. It is powered by an updated family of turbo-charged direct-injection petrol and diesel engines delivering up to 211 hp with CO2 emissions as low as 98 g/km.
The new A-Class is available with Mercedes-Benz' first double-clutch seven-speed automatic transmission (7G-DCT), and the range also advances the company's policy of ensuring that as many people as possible enjoy the protection of advanced safety features, with the innovative Collision Prevention Assist headlining a comprehensive list of active and passive protection features fitted as standard.
The new Mercedes-Benz A-Class is the second model in what will eventually become a family of compact front-drive cars from Mercedes-Benz, which began with the latest B-Class. But while the B-Class is focused on family usage, providing the space of a much larger saloon within a compact-car footprint, the A-Class has a more dynamic role to play, as is evident in its dramatic styling.
Mercedes-Benz has also introduced a new 2.0-litre direct-injection turbo-charged petrol engine to its Mercedes-Benz A-Class range generating 211 hp - sufficient to propel the car from zero to 62 mph in 6.6 seconds and on to a 149 mph top speed. This is standard with the exclusive range-topping Engineered by AMG specification, as is the 7G-DCT double-clutch automatic transmission, along with AMG-inspired styling, trim, equipment and chassis tuning.
Two new diesel engines also make their debut in the third-generation A-Class, giving the car potential fuel economy of 74.3 mpg with CO2 emissions down to 98 g/km.
At the other end of the spectrum, the 2.2-litre 220 CDI engine generates 170 hp and 350 Nm of torque. In conjunction with the standard 7G-DCT transmission, it accelerates the A-Class from 0-62 mph in 8.2 seconds. It meets the EU 6 emissions standard not due to come into force until 2015, while posting a combined fuel economy of 64.2 mpg and CO2 emissions of just 115 g/km, demonstrating that with the new Mercedes-Benz A-Class, performance and efficiency are not mutually exclusive.
Designers and engineers are rarely given the luxury of a completely blank sheet of paper when starting work on a new car, yet that is precisely the opportunity Mercedes-Benz engineers were given for the new A-Class. Longer, wider and lower than the previous two versions, the latest model is a more emotive and dynamically engaging car that's little changed from the radical Concept A-Class given a wildly enthusiastic reception at the 2011 Shanghai Auto Show.
It is a progressive and highly sculpted five-door two-box model, now based on a monocoque construction rather than the sandwich floor assembly of the previous two generations. This not only dramatically reduces the overall height of the car, but it also lowers the seating position of the occupants by 174 mm, which in turn brings down the centre of gravity by 24 mm to allow much more dynamic and agile driving characteristics. These are even more emphatic in the 15 mm lower AMG Sport and specifically tuned Engineered by AMG versions.
The exterior cleverly mixes sharp edges and tautly drawn convex and concave surfaces which seem to constantly change with the angle of the light, particularly along the sides. The long, bold front leads into a pronounced V-shape, culminating in the radiator grille with the central Mercedes-Benz star between double slats, or a single slat dividing a unique diamond grille in the Engineered by AMG version. The headlamps and the light functions within them are key elements of the design concept.
The design emphasises the class-leading aerodynamics of the new Mercedes-Benz A-Class, with its drag coefficient of Cd 0.27. This is especially apparent in the smooth arc of the roof, which finishes in a flat edge, and a spoiler which conveniently hides the aerials. The tailgate is another interplay of convex and concave surfaces which further demonstrates the interaction between design and aerodynamics: the surface of the tail lights improves airflow around the car through defined break-away edges.
The interior of the A-Class represents a dramatic step forward in the quality of materials used, as well as the consistency of design. The front of the cabin adopts an aviation-inspired theme, with the dashboard shaped like the wing of an aircraft and the round air vents reminiscent of jet engines. Meticulous attention to detail is apparent everywhere, from the 'cool touch' real metal electroplated trim embellishers to the free-standing display screen with a black piano lacquer-look front panel and a flush-fitting silver frame.
The rear provides generous room for three passengers, despite looking as though it has only two individual seats. A 341-litre luggage area can be expanded to 1,157 litres with the rear seats folded. In all models the seat backrests are split 2/3:1/3.
Altogether, there are seven direct-injection turbo-charged engine options in the new A-Class, all characterised by high specific outputs, flexible performance thanks to strong torque across a wide rev range, outstanding efficiency and excellent refinement.
In addition to the new 211 hp 2.0-litre petrol unit (A 250 BlueEFFICIENCY) and the new 109 hp 1.5-litre (A 180 CDI BlueEFFICIENCY) and 170 hp 2.2-litre (A 220 CDI BlueEFFICIENCY) turbodiesels, there are two further petrol units (A 180 BlueEFFICIENCY and A 200 BlueEFFICIENCY) and two more diesels (A 180 CDI BlueEFFICIENCY 7G-DCT and A 200 CDI BlueEFFICIENCY), which were introduced with the latest B-Class. All engines feature ECO start/stop as standard.
The A 180 BlueEFFICIENCY is powered by a 1.6-litre 122 hp engine, while the A 200 BlueEFFICIENCY uses a 156 hp version. The diesel engines are 1.8-litre units; a 109 hp option is fitted in conjunction with the 7G-DCT transmission in the A 180 CDI BlueEFFICIENCY, and a 136 hp variant in the A 200 CDI BlueEFFICIENCY.
A six-speed manual gearbox is standard with the A 180, A 200, the 1.5-litre A 180 CDI and the A 200 CDI, while the A 250, the 1.8-litre A 180 CDI and the A 220 CDI have the 7G-DCT transmission. This is an option with the A 180, A 200 and A 200 CDI. Fuel consumption has been reduced by up to 35 per cent compared with the preceding models, despite considerable power increases.
The petrol engines are all-aluminium M 270 turbo-charged direct-injection 16-valve four-cylinder units. They are extremely versatile engines which are already being phased into larger Mercedes-Benz models to help bring down fuel consumption and emissions. They employ technology first introduced in 2010 with the ultra-modern BlueDIRECT V6 and V8 engines for the S-Class. The combustion process is based on third-generation Mercedes-Benz direct- injection technology with highly precise, multiple piezo-injections.
With the exception of the new 1.5-litre engine, now in its sixth generation and specially adapted by Mercedes-Benz for use in the A-Class, the diesel engines are developments of the OM 651 fourth-generation 2.2-litre four-cylinder unit premiered in 2008. Since then the OM 651 has been setting standards for performance, torque, economy, emissions and smooth running. It is in more widespread use than any other Mercedes-Benz diesel engine.
The instantaneous response of the engines and the slick operation of the six-speed manual and triple-mode (Economy, Sport and Manual) 7G-DCT transmissions in the new A-Class is complemented by the agile chassis, which features a four-link rear axle, electro-mechanical power steering, powerful all-round disc brakes and advanced driver assistance functions such as specially tuned ESP® Electronic Stability Control.
There are three different suspension tunings, with a comfort set-up for standard, SE and Sport models, a sportier 15 mm lower arrangement for AMG Sport variants and the ultimate AMG-tuned system in the A 250 BlueEFFICIENCY Engineered by AMG.
All benefit from the more dynamic new proportions and lower centre of gravity of the latest Mercedes-Benz A-Class. During development, the engineers made intensive use of the driving simulators at the Mercedes-Benz development centre in Sindelfingen to create a digital profile of the driving dynamics of the new A-Class. This enabled them to achieve the right balance of agility, nimbleness, stability and comfort required for each version before a single prototype had been built.
In keeping with every new model introduction from Mercedes-Benz, the latest A-Class extends the protection afforded by advanced safety technology to as many people as possible by offering features that are the preserve of only the most expensive cars from some brands.
In the A-Class, this starts with an extremely robust body shell incorporating extensive areas of high-strength and ultra-high-strength steels for rigidity with lightness, and includes the innovative radar-based accident warning system, Collision Prevention Assist, which is fitted as standard. This gives visual and audible warnings to alert a distracted driver to the possibility of a nose-to-tail collision, and prepares the standard Adaptive Brake Assist feature for the most effective braking response as soon as the driver hits the brake pedal.
The Attention Assist feature to recognise and alert a drowsy driver is also standard, along with Adaptive Brake Assist incorporating Hold and, on manual models, Hill-Start Assist. This primes the brakes for maximum stopping effect in a possible emergency, adds to convenience by holding a stationary car without the driver having to keep a foot on the brake pedal and prevents the car from rolling backwards when setting off on uphill gradients. Seven airbags, including a driver's knee airbag, and an Active Bonnet to provide additional pedestrian protection are also fitted to every Mercedes-Benz A-Class as standard.
Available features include Lane-Keeping Assist and Blind Spot Assist, Speed Limit Assist, Active Park Assist with Parktronic, Distronic Plus autonomous acceleration and braking to maintain a gap to the car ahead, the Mercedes-Benz Intelligent Light system and the anticipatory Pre-Safe® occupant protection feature.
The new A-Class is optionally available with COMAND Online in-car internet services, and in 2013 it will be offered with seamless integration of the Apple iPhone® in conjunction with a revolutionary new user interface design. Highlights include advanced navigation software from Garmin, with internet-based real-time traffic information, online destination searches and 3-D map display.
COMAND Online provides internet access via a web-enabled mobile phone, plus various Mercedes-Benz services on the move. These include weather information, news, and a special destination search via Google, as well as the option of downloading a route previously configured on a PC using Google Maps.
Exterior
Mercedes-Benz has taken a dramatically different approach to the design of the new A-Class. Where the previous two models were essentially pragmatic - ingeniously packaging the space of a large saloon into a car with the footprint of a city runabout - the new A-Class adds rewarding elements of dynamism and excitement to elevate it above its compact front-wheel-drive five-door hatchback rivals.
Radical, progressive and emotive, it brings the sculpted look and feel of the latest Mercedes-Benz design idiom to the compact car class.
The key dimensions are in themselves enough to show just how much the A-Class has changed. At 4,292 mm long, 1,780 mm wide and 1,433 mm tall, it is 409 mm longer, 16 mm wider and almost 180 mm lower than the model it replaces.
Its radical form language was first seen in the Concept A-Class at the Shanghai Auto Show of 2011. That highly acclaimed design has now been transferred to the production model - a huge challenge in a car of compact dimensions, which had to match its rakish and exciting appearance with a usable and practical five-seater interior.
Design at Mercedes-Benz always begins with an internal competition among all the company's designers. The winning entry for the exterior of the Mercedes-Benz A-Class came from Englishman Mark Fetherston, a graduate of Coventry University's School of Transport Design, who has worked at Mercedes-Benz since 1999. Fetherston has excellent design form at Mercedes-Benz - he also designed the exterior of the SLS AMG gullwing supercar.
For the flowing, sculpted shape of the A-Class, he was influenced by the patterns of sand dunes and winter landscapes - and even the sleek lines of the Concorde - and was able to take advantage of the encouragement given to the design team by the Mercedes-Benz Board to be more progressive.
The sides of the new A-Class are characterised by sharply defined edges and tautly drawn convex and concave surfaces, which seem to constantly change as the light catches them. The pronounced front end meets in a prominent V-shape, with the Mercedes-Benz star mounted in a two-louvre grille in either chrome, silver, black or body colour, depending on model.
There are three lower air intakes in the bottom section of the bumper. The A-Class Engineered by AMG has a single-louvre diamond-pattern grille and black edges around the air intakes, with a red highlight line in the central section.
The headlamp units are a key element of the frontal design. The light modules have been arranged to deliver a flare-effect for the daylight running lamps and turn indicators, creating an instantly identifiable visual signature for the new A-Class. Bi-xenon headlamps and LED daytime running lights are fitted to the A-Class Engineered by AMG.
The new A-Class has a class-leading drag co-efficient figure of Cd 0.27. Nowhere is this more apparent than in the dynamic and smooth arc of the roof, which finishes in a spoiler that neatly hides the aerials and lends structure to the whole assembly.
Along the flanks, a rising beltline in either black or chrome enhances the car's pronounced wedge profile, while another line rises from the mid-point of the front wheel arches to create powerful shoulder muscles at the rear, giving the new Mercedes-Benz A-Class a coupé-like stance. Between these two crisp lines are sensuously moulded sculptured panels.
Dynamic sills add an athletic finishing touch, particularly pronounced in the A-Class AMG Sport, which rides 15 mm lower than other models, and the A-Class Engineered by AMG with its AMG sports suspension.
The interplay of convex and concave surfaces and taut edges is repeated at the rear. The tail lights - LED units in the A-Class Engineered by AMG models - continue the line of the muscular shoulders back towards the rear. Their horizontal orientation emphasises the greater width of the new model.
The tail-light clusters are also pointers to the superior aerodynamics of the new A-Class: not only are they a design feature in themselves, but their carefully shaped break-away edges have been designed to improve airflow from the rear of the car.
Interior
The interior of the new A-Class was also inspired by two concept cars. The starting point was the Mercedes-Benz Aesthetics No 2 sculpture revealed at the 2011 Detroit Auto Show. This was then incorporated into the Concept A-Class, which was created at the Mercedes-Benz Advance Styling Studio in the northern Italian city of Como in time for the Shanghai Auto Show in September of the same year.
If the dash area, vents and instruments were inspired by the world of aviation then the seating areas, space, quality and attention to detail have been designed to give the spacious feel of a far larger car.
The objective was to complement the sleek look of the exterior while giving the Mercedes-Benz A-Class a high-quality appearance and feel unique in its segment through the design and the choice of materials, colours and textures.
The sweep of the dash continues the aircraft wing-inspired theme of other recent new models from Mercedes-Benz. It incorporates five circular air vents with electro-plated outer rings on SE versions and above. Airflow through these vents is controlled by cruciform nozzles reminiscent of jet engines. In the A-Class Engineered by AMG these vents feature a red insert matching the car's front lower centre grille. The electro-plating process gives the nozzles a tactile metal finish with a cool-touch effect, and has been extended to all trim elements.
The instrumentation and control screen appear in the upper part of the dash, while a broad lower section contains the switchgear and control buttons. The production process used for the lower section allows a wide diversity of soft-touch surfaces to further emphasise the quality and attention to detail within the cabin.
The instrument cluster is made up of two large round dials, each with a smaller dial set within. The dial faces are either black or silver with a chequered flag design, depending on model. Likewise, the dial needles are red or white, according to the trim level.
To the right of the instrument panel is a free-standing 5.8-inch tablet-style colour display screen with a black piano lacquer-look front panel and a flush-fitting silver frame. This is linked to the Audio 20 entertainment system or the option Audio 20 system with Media interface.
The new A-Class has been configured so that an Apple iPhone® can be fully integrated into the operating and display system via the Drive Kit Plus special app.
For all its rakish looks and compact dimensions, the A-Class is a full five-seater hatchback, but the rear accommodation has cunningly designed to look like two individual seats. All models from SE have sports seats with integrated head restraints, and sports pedals with rubber studs.
A sports three-spoke multi-function steering wheel with leather trim, perforated in the grip areas, is fitted to SE and Sport versions of the new Mercedes-Benz A-Class, while AMG Sport and Engineered by AMG versions have a flat-bottomed sports steering wheel trimmed in nappa leather.
The rear seat backrests are split 2/3:1/3 and the two sections can be folded individually to expand the standard 341-litre luggage are to a maximum of 1,157 litres. The luggage area allows items more than a metre wide to fit between the wheel housings.
Engineering
Nothing illustrates the new, more dynamic character of the latest A-Class more than the way it is constructed. In place of the sandwich-floor assembly of the previous two generations, there is now an advanced steel monocoque layout that brings about significant reductions in the height of the car and the seating positions which, in turn, lowers the centre of gravity. The outcome is sharper, more agile, nimbler handling with uncompromised passenger accommodation.
There are three all-independent suspension options which adjust the balance between sportiness and handling to suit the various model packages. All versions have fuel-saving electro-mechanical power-assisted steering, powerful all-round disc brakes incorporating the Mercedes-Benz Hold function, an electronic parking brake and the latest driver assistance systems.
Chassis
The sandwich-floor body construction of the previous two generations of A-Class, which placed the engine partly in front of and partly beneath a twin-floor passenger cell, has been replaced by a sophisticated steel monocoque in the latest model. This has not only brought about a significant reduction in the car's overall height, which has been reduced by 160 mm, and seating positions, which are 174 mm lower, but it has lowered the centre of gravity by 24 mm - an ideal starting point for a car engineered to deliver more dynamic and agile handling.
This is underscored by the structural design of the body-in-white, which features 67 per cent high-strength or ultra-high-strength steels. This increases the rigidity of the chassis from a dynamic behaviour perspective and ensures the new A-Class more than meets the stringent Mercedes-Benz safety standards, which far exceed anything demanded by legislation anywhere in the world.
There is a new bulkhead and floor, an integral support frame as a deformation element, a length of 435 mm over which to dissipate crash energy and load distribution over several planes. Altogether, three longitudinal planes allow impact energy to be absorbed in a controlled manner.
The support frame is the attachment point for the front axle and steering assembly as well as the torque support for the transversely mounted engine and gearbox. It is made up of several steel plates and a hydroformed tube, and is connected by two aluminium struts to the aluminium radiator mount.
A plastic crash wedge at the rear of each front wheel arch prevents the wheel from sliding beneath the door in an impact, thus ensuring that the doors are still capable of being opened after an impact.
Mercedes-Benz has developed what it calls 'skate runners' to discharge frontal impact forces into the floor, which features four straight longitudinal members. To protect the passenger cell in a side impact there are rigid structures which include a pole support fitted diagonally between the central tunnel and the floor sidewalls. This is intended to prevent the floor being torn open even in a side impact with a tree.
High-strength steels in the upper part of the B-pillar minimise intrusion, but the lower part of the pillar is made from softer steels so that crash energy is dissipated in a controlled manner. The B-pillars also house something referred to by Mercedes-Benz engineers as 'vampire's teeth' - small tooth-like recesses which prevent the seat-belt retractor from causing cracks that might affect the body's structural integrity in a crash.
Suspension
The new A-Class has all-independent suspension with three different levels of tuning to strike the ideal balance between comfort and sportiness according to the model variant. Suspension engineers made extensive use of the driving simulators at the Mercedes-Benz development centre in Sindelfingen, compiling a digital profile of the car's dynamic responses as part of the development process before a single prototype was built.
All three suspension arrangements rely on a redesigned MacPherson strut system at the front and a new four-link rear axle developed for the new Mercedes-Benz family of compact front-wheel-drive cars. This, combined with the lower centre of gravity of the latest Mercedes-Benz A-Class, provides a perfect platform for excellent dynamic behaviour.
The four-link rear axle is configured so that forces are absorbed by three control arms and one trailing arm per wheel. This means that longitudinal and lateral influences on the suspension are absorbed virtually independent of each another. The wheel carriers and spring links are made of aluminium to reduce unsprung weight. The goal was to achieve high lateral agility with high straight-line stability and the minimum of slip on the rear axle.
All three suspension configurations deliver exemplary levels of comfort with precise, agile responses, low degrees of roll and low start-off pitch. The A-Class has been set up introduce mild understeer at higher degrees of lateral acceleration so that the driver can control changes in direction with low steering input but high steering precision.
Standard comfort suspension is fitted to A 180, SE and Sport models. AMG Sport versions have the Dynamic Handling Package (optional on Sport), which lowers the ride height by 15 mm and introduces firmer springs and dampers plus AMG multi-spoke 18-inch alloy wheels. Direct-Steer is also part of the Dynamic Handling Package, adding an extra element of agility and precision. Engineered by AMG models feature modified AMG sports suspension.
The latest ESP® Electronic Stability Programme includes Torque Vectoring Brake, which helps to control any tendency towards oversteer in fast cornering by applying slight brake pressure to the outer rear wheel. It has been designed to intervene gently so that skilled and experienced drivers can extract maximum enjoyment out of the car without ever reaching a potentially critical situation.
Steering
The new A-Class features redesigned electro-mechanical steering, engineered to give drivers maximum enjoyment by delivering fast, accurate responses while saving fuel by drawing power assistance from the engine only when the car is turning. A turning circle of just 11 metres adds to the practicality, especially in urban driving conditions, of the A-Class.
The electric motor, which provides servo assistance, is mounted directly on the steering gear. The steering permits various assistance functions in conjunction with the ESP® control unit. For example, it can compensate for the effect of crosswinds and cambered roads, counter the torque-steer effect found in some front-wheel-drive cars, keep the car straight when braking on surfaces where the levels of grip differ from left to right, and counter-steer should the car nudge towards oversteer.
It also makes the optional Active Park Assist with Parktronic. Active Park Assist with Parktronic measures potential parking spaces through two ultrasonic sensors on the front bumper. If the space is large enough for the car, the system operates the electro-mechanical power steering while the driver works the accelerator and brake.
AMG Sport and Engineered by AMG versions of the A-Class come as standard with Mercedes-Benz' Direct-Steer system, which provides variable hydraulic assistance that reduces as speed increases and adds a variable ratio that changes according to the steering angle.
The ratio is indirect when steering straight ahead, thus ensuring exceptional stability, but increases rapidly once a five-degree steering angle has been applied, becoming extremely direct from a steering angle of 100 degrees. As a result, the driver need make only relatively small steering movements when manoeuvring in confined areas or through a series of tight corners. The variable ratio is achieved through a steering rack with different teeth profiles.
Brakes
The Mercedes-Benz A-Class comes as standard with powerful all-round disc brakes. The rear calipers and brake boosters are made from aluminium to reduce unsprung weight. The Mercedes-Benz Hold function is also standard - a slightly firmer push of the brake pedal once the car comes to rest ensures it is held without the driver having to maintain pressure on the pedal. It disengages as soon as the driver touches the accelerator.
Manual versions also have Hill-Start, which momentarily maintains brake pressure while the driver's foot moves from the brake pedal to the accelerator. This ensures the car does not roll backwards when setting off on uphill gradients.
The Hill Start Assist function is incorporated into the standard-fit Adaptive Brake Assist feature, which works in conjunction with the Anti-lock Brakes (ABS) to reduce stopping distances in an emergency. Adaptive Brake Assist is linked to the ASR acceleration skid control and the active yaw control units.
Adaptive Brake Assist comes into operation as soon as the driver abruptly lifts off the accelerator pedal - the first reaction in a potential emergency. It recognises the urgency of the situation and primes the brake pads so that they come into light contact with the brake discs. If emergency braking proves to be necessary, pressure can therefore be achieved instantly. During wet weather the system dries the brake discs by maintaining gentle but imperceptible pressure between brake pads and discs.
An electronic parking brake is standard on all models, helping to free more storage space between the front seats. In models fitted with the 7G-DCT transmission it releases automatically as the car moves away so long as the driver's seat belt is fastened. If activated at speeds of more than 2 mph it also serves as an emergency brake through the ESP® system.
Engines and Transmissions
A dynamic new petrol engine, an ultra-economical new turbodiesel and a performance turbodiesel make their debuts in the new A-Class. The new petrol engine is a 2.0-litre development of the 1.6-litre unit first seen in the new B-Class, and perfectly complements the dynamic design and agile handling of the new A-Class. It develops 211 hp and 350 Nm of torque, accelerating the A-Class to 62 mph in 6.6 seconds and on to a top speed of 149 mph.
It powers the A 250 BlueEFFICIENCY AMG Sport and the A 250 BlueEFFICIENCY Engineered by AMG, driving through the Mercedes-Benz 7G-DCT seven-speed double-clutch automatic transmission, which is fitted as standard to both models.
The first new diesel engine is a 1.5-litre unit that develops 109 hp and 260 Nm of torque, but of greater significance is that it allows the new A-Class to attain a combined fuel consumption figure of 74.3 mpg with CO2 emissions as low as 98 g/km. It is available in SE, Sport and AMG Sport versions.
This frugal and clean diesel powerplant is joined by the range-topping new 2,143 cc turbodiesel engine that powers the A 220 CDI BlueEFFICIENCY AMG Sport. This dynamic unit develops 170 hp at 3,400-4,000 rpm and a muscular 350 Nm of torque available from 1,400-3,400 rpm, good for an 8.2 second sprint to 62 mph and a 137 mph top speed.
Only available with the 7G-DCT dual clutch transmission, this lightweight engine returns 64.2 mpg on the combined cycle and posts a CO2 emissions figure of just 115 g/km. These excellent figures illustrate just how advanced this new engine is - compared with the previous generation A 200 CDI, the new A 220 CDI BlueEFFICIENCY is 30 hp and 50 Nm more powerful, yet is 11.9 mpg more economical and 34 g/km cleaner on CO2 emissions.
These three new advanced engines join four further powerplants that made their debut in the new B-Class.
The familiar 1.6-litre 122 hp petrol engine is available in standard, SE and Sport versions of the A 180 BlueEFFICIENCY and a 156 hp version of the same engine is offered in the A 200 BlueEFFICIENCY Sport and AMG Sport. All except the standard A 180 BlueEFFICIENCY are available with the sophisticated 7G-DCT transmission as an alternative to the standard six-speed manual.
The highly economical 1.8-litre diesel unit develops 109 hp and 250 Nm of torque in the A 180 CDI BlueEFFICIENCY SE, Sport and AMG Sport models - available with the 7G-DCT transmission. A 136 hp version of the same engine also powers the A 200 CDI BlueEFFICIENCY Sport and AMG Sport. This most powerful diesel engine derivative is available with manual or 7G-DCT transmission.
The petrol engines
The all-aluminium M 270 turbo-charged direct-injection engine makes its debut in the new A-Class. This 1,991 cc unit develops 211 hp at 5,500 rpm and 350 Nm of torque from 1,200-4,000 rpm, and is the perfect match for the engaging design and dynamic handling of the new Mercedes-Benz A-Class.
All three M 270 engines are 16-valve four-cylinder units with twin overhead camshafts. They are extremely versatile engines, which are already being phased into larger Mercedes-Benz models to successfully lower fuel consumption, emissions and production costs. Their versatility is exceptional - they can be installed both transversely (M 270) or longitudinally (M 274), combined with front, rear or 4MATIC all-wheel drive, and paired with manual, automatic torque converter or 7G-DCT dual clutch transmissions.
They employ technology first introduced in 2010 with the ultra-modern BlueDIRECT V6 and V8 engines for the Mercedes-Benz S-Class. The combustion process is based on third-generation Mercedes-Benz direct-injection with highly precise, multiple piezo-injection technology. Mercedes-Benz is a pioneer in this field - in 2006 Mercedes-Benz was the first car manufacturer to introduce direct-injection with spray-guided combustion into series production.
Newly developed piezo-injectors allow up to five injections per power stroke. In the warm-up phase this enables particulate emissions to be reduced by more than 90 per cent. The overall result is that all emission figures, including particulates, already surpass Euro 6 emissions standards not due to be enforced until 2015.
Piezo-injectors have numerous advantages in petrol engines compared with conventional multi-hole solenoid valves. The fuel vaporises up to four times as fast, the jet of fuel penetrates less deeply into the combustion chamber, and the injectors are able to deliver minute quantities of fuel with exceptional precision. This prevents fuel from being deposited on the combustion chamber walls, resulting in significantly reduced particulate emissions.
An electrical charge is applied to the piezo-ceramic injectors, which changes their structure in microseconds, and with a precision of just a few thousandths of a millimetre. The central component of a piezo-electric injector is the piezo-stack, which directly controls the metering needle. With a response time of just 0.1 milliseconds, the injection of fuel can be sensitively and precisely adjusted to the current load and engine speed, reducing emissions, fuel consumption and combustion noise.
The third-generation direct-injection system also features rapid multi-spark ignition (MSI). Following the first spark and a brief combustion period, the coil is recharged rapidly and there is a further spark. The MSI system enables up to four sparks within one millisecond. MSI can vary both the timing of the sparks and the combustion period to suit the current operating point. This provides scope for the best possible combustion, which further reduces fuel consumption. Fuel savings of up to 4 per cent alone are possible by the use of piezo-electric injection technology combined with MSI.
Mercedes-Benz has developed an innovation known as CAMTRONIC for its 1.6-litre engine. CAMTRONIC is a load management system which controls intake cut-off and intake valve lift adjustment, and is a first in a turbo-charged direct-injection petrol engine. It reduces throttling losses under partial load, lowering fuel consumption by three to four per cent. In day-to-day driving, which typically has a high proportion of partial load operation, the potential saving is even greater, with fuel savings of up to 10 per cent. It was developed completely in-house by the Mercedes-Benz Technology Centre in Stuttgart and the Daimler engine plant in Berlin.
The high specific outputs of the small-capacity M 270 engines are the result of turbo-charging, which forces intake air into the combustion chambers at a pressure of up to 1.9 bar, with the turbine vanes rotating at up to 230,000 rpm.
The turbo-charger has been designed to deliver high torque even at low engine speeds. It is integrated into a newly developed manifold turbo-charger module, positioned in front of the engine for the best possible cooling. Separate exhaust ducting from the cylinders to the turbo-charger and a high exhaust temperature of up to 1,050 degrees Celsius make maximum use of the exhaust gas energy, producing a high output and outstanding responsiveness.
By using a combination of direct-injection and variable adjustment of the intake and exhaust camshafts, the engines are also able to exploit the advantages of so-called scavenging. This involves a partial overlap of the opening times of the intake and exhaust valves, causing some of the cold intake air to flush the hot exhaust gas from the cylinder into the exhaust manifold, which considerably improves charging.
At low engine speeds the turbo-charger also responds much more rapidly, significantly reducing turbo-lag when moving off. The direct-injection system ensures that the fresh gas is not yet mixed with fuel when it enters the cylinder, as would be the case in engines with manifold injection. No unburned fuel is therefore flushed into the exhaust manifold.
As a result, the 1.6-litre engine in the A-Class delivers its 200 Nm maximum torque at 1,250 rpm, maintaining that twist action through to 4,000 rpm. The 2.0-litre version posts even better results - its maximum torque of 350 Nm is available from 1,250 rpm through to 4,000 rpm, which means that it leads the field for four-cylinder engines.
A new thermal management system has also been developed for these powerplants. In cold state, a switchable water pump with flow-optimised ball valve ensures that no coolant flows through the engine, allowing the combustion chambers to heat up quickly. The thermostat is electronically controlled and the coolant temperatures are adjusted according to driving style and ambient conditions.
The variable vane oil pump operates with two pressure stages. At low engine speeds and loads the pump runs at a pressure of 2.0 bar and the oil-spray nozzles for piston cooling are switched off. The high-pressure stage is activated at higher loads and engine speeds. As a result, the lubrication and cooling of the engine requires significantly lower drive energy than with an uncontrolled pump.
The coolant ducting in the cylinder head is also new. The water mantle is a two-piece construction to improve flow. This leads to specific increases in flow speeds and heat dissipation at certain points, accompanied by a reduction in pressure losses throughout the coolant circuit. This has made it possible to reduce the power output of the water pump despite an increase in engine output.
As it warms up, the flow of coolant is regulated by a triple-phase thermal management system so that it rapidly reaches normal operating temperature. Initially the coolant remains at rest in the engine. It then circulates in the engine circuit, but bypasses the radiator. When a temperature of 105° Celsius has been reached the radiator is included in the circuit.
To ensure absolute smoothness at all times, there are two Lanchester balancer shafts in the bottom of the 2.0-litre engine block to counter the secondary inertia forces inherent in four-cylinder in-line engines. Mercedes-Benz is the first car manufacturer to use anti-friction bearings to balance these masses.
This is achieved via cylinder roller bearings, with axial forces from the gearing taken up by a ball bearing. This arrangement not only improves smoothness, but also helps to lower fuel consumption by reducing friction. Because of its more favourable connecting rod configuration, the 1.6-litre engine does not need Lanchester shafts.
Friction is also minimised by a reduction in flow through the oil and water pumps, low-friction pistons, piston rings and cylinder walls, plus the new thermal management system and chain drive.
The engine and transmission are mounted at four points - by an engine mounting, a transmission mounting and two pendulum supports. These are specially configured for the needs of the high-torque engines to minimise noise. The hydraulic damping integrated into the transmission mounting also contributes significantly to driving comfort.
The turbodiesel engines
Two new turbodiesel engines make their debut in the new A-Class. Features include sixth generation common-rail injection with a rail pressure of 1,600 bar, low-pressure Exhaust Gas Recirculation and variable geometry turbo-charging.
The 1.5 litre engine in manual versions of the A 180 CDI BlueEFFICIENCY generates 109 hp and a healthy 260 Nm available from 1,750 rpm to 2,500 rpm, and achieves CO2 figures which start at just 98 g/km, making the new A-Class among the most environmentally friendly compact diesels in its sector.
This frugal and clean diesel powerplant is joined by the range-topping new 2,143 cc turbodiesel engine that powers the A 220 CDI BlueEFFICIENCY. This dynamic unit develops 170 hp at 3,400-4,000 rpm and a muscular 350 Nm of torque available from 1,400-3,400 rpm, good for an 8.2 second sprint to 62 mph and a 137 mph top speed.
Only available with the 7G-DCT dual clutch transmission, this engine features a weight-optimised crankshaft with individual bearing covers bolted from below and four counterweights, enabling it to tip the scales at around six kilograms less than a longitudinally installed OM 651 engine of the same displacement. The single-stage turbo-charger has larger dimensions than that in the other less-powerful variants.
It returns a 64.2 mpg on the combined cycle and posts a CO2 emissions figure of just 115 g/km. These excellent figures illustrate just how advanced this new engine is - compared with the previous generation A 200 CDI, the new A 220 CDI BlueEFFICIENCY is 30 hp and 50 Nm more powerful, yet is 11.9 mpg more economical and 34 g/km cleaner.
These two new engines join the 1.8-litre turbodiesel powerplant developed by Mercedes-Benz for the new B-Class and now available in the A-Class. The A 180 CDI BlueEFFICIENCY in tandem with the 7G-DCT double-clutch automatic transmission employs a 109 hp version of the 1.8-litre diesel engine, while the A 200 CDI BlueEFFICIENCY uses a 136 hp version of the engine alongside a six-speed manual gearbox or the 7G-DCT.
The new 1.5-litre engine, which has been given the in-house designation OM 607, is notable for its low weight. Components specific to Mercedes-Benz include the engine mountings of the M 270 petrol engine as well as a bespoke two-mass flywheel. The starter, the alternator and the refrigerant compressor also come from the Mercedes-Benz modular system, and are driven by a belt with six grooves. Like all Mercedes-Benz engines, the OM 607 was required to pass an extensive test programme involving bench and endurance runs.
Mercedes-Benz engineers put the engine through a rigorous schedule to improve NVH (noise, vibration and harshness) and driveability. Coordination work also went into the ECO start/stop function which is standard on all versions of the A-Class. This feature, specific to Mercedes-Benz, operates at temperatures down to minus 10 degrees Celsius so that it can make a greater contribution to fuel economy.
All three diesel engines in the Mercedes-Benz A-Class are extremely efficient thanks to state-of-the-art injection technology and turbo-charging. The 1.8-litre units are developments of the OM 651 fourth-generation 2.2-litre four-cylinder unit premiered in 2008. Downsizing for the A-Class has been achieved by shortening the piston stroke from 99 to 83 mm. They have an aluminium cylinder head and a cast-iron block.
Compared with the 2.2-litre version used in the rear-wheel-drive C-Class and E-Class models, they feature a modified belt drive and air ducting and a new turbo-charger mounting to suit transverse installation. Cylinder spacing of 94 mm and spur-gear camshaft drive make them particularly compact.
Third-generation common-rail technology, with the rail pressure increased to 1,800 bar and a maximum ignition pressure of 200 bar, allows both versions of the engine to attain their high specific outputs. This is aided by a two-piece water jacket in the cylinder head to provide optimum cooling.
A number of engineering measures further enhance fuel efficiency. The oil injector nozzles and the water pump become active only when necessary, reducing energy drain on the engine, while the oil pump reduces oil flow in a controlled manner. The two Lanchester balancer shafts which give the engines their exemplary smoothness under all loads run in low-friction roller bearings rather than conventional plain bearings. The long connecting rods also help reduce friction and therefore improve fuel economy.
Refinement is further improved by a dual-mass flywheel specifically designed to isolate crankshaft vibrations in engines developing high torque at low revolutions.
Since its world premiere in 2008 the OM 651 has been setting standards in terms of performance, torque, economy, emissions and smooth running. It is in more widespread use than any other Mercedes-Benz diesel engine and serves as a model of efficiency and power from the new A-Class right up to the S-Class.
Thanks to BlueDIRECT technology and highly precise piezo-injection, the engines easily surpass the anticipated Euro 6 emission standards coming into force from 2015. For diesel engines the regulations are particularly stringent in relation to particulate limits, but Mercedes-Benz has been able to better these requirements without recourse to additional exhaust after-treatment.
ECO start/stop
All versions of the new A-Class are fitted with intelligent and extremely efficient ECO start/stop technology, which ensures that no fuel is used and no emissions are created when the car is stationary in traffic. The system seamlessly stops the engine when the car is at rest and swiftly restarts it the moment the driver wishes to pull away.
It does not require any intervention by the driver. With the six-speed manual gearbox, the engine switches off as soon as the driver applies the brakes, shifts the transmission lever into neutral and releases the clutch. The engine restarts when the driver presses the clutch.
With the 7G-DCT dual-clutch automatic transmission, the ECO start/stop function deactivates the engine when the driver presses the brake pedal and the car comes to rest. The engine restarts automatically when the driver's foot is removed from the brake pedal or the accelerator pedal is pressed.
A number of defaults ensure it functions only under full driver control and when certain safety parameters have been met. Naturally, it will work only when the car is stationary. In manual versions, the brakes must be applied, the transmission must be in neutral and the clutch pedal must be released. With the 7G-DCT gearbox, the shift lever must be in Drive or Neutral.
In both cases, there must be no steering wheel movement, the doors and bonnet must be closed and the driver's seat belt must be fastened. The driver's foot must be on the brake pedal or the Hold function must be active. The engine will restart if it detects a vehicle-related precondition, such as extensive use of the air conditioning system.
The ECO start/stop system employs a sensor which monitors the angle of the crankshaft and the position of each cylinder. The sensor determines which cylinder is in the best position for ignition when restarting to ensure smooth and instantaneous ignition. Mercedes-Benz direct-start technology ensures the system operates spontaneously and with little noise. Fuel is injected directly and ignited during the piston's compression stroke, allowing the engine to fire up with little assistance from the starter.
Advanced software management ensures the ECO start/stop system operates only when the engine and cabin have both reached the correct temperature. The driver can switch the system off if required. To handle the requirements of the ECO start/stop system, the starter motor has been modified so that it can cope with eight times the usual number of starting procedures so that even in continuous urban driving it will last the car's lifetime. A second battery supports the on-board electrical system.
7G-DCT dual-clutch automatic transmission
The 7G-DCT dual-clutch automatic transmission, which made its debut in the new Mercedes-Benz B-Class, is available in the majority of new A-Class models, and standard on both the petrol-powered A 250 BlueEFFICIENCY and the A 220 CDI BlueEFFICIENCY diesel-powered variants.
It delivers the comfort and convenience of a full automatic system with the fuel economy of a manual transmission. It allows drivers to exercise full manual control via paddles mounted behind the steering wheel, with gear changes taking place far faster than even the most skilled driver can execute with a manual transmission. There are three shift programmes - Economy, Sport and Manual.
In ECONOMY, gearshifts are fully automatic, but take place at the lowest possible engine revolutions to promote the most fuel-efficient driving style. In SPORT, the gear changes are also fully automatic, but are completed extremely rapidly to minimise torque reductions and maintain momentum.
In both modes the driver can intervene to make a manual shift at any time using the steering wheel paddles. The transmission reverts to automatic mode if no manual gear changes are made within the next 12 seconds, or after a longer delay when driving downhill or on winding roads. MANUAL mode hands full control to the driver, and the shifts take place even faster than in SPORT.
The two wet multi-disc clutches running in an oil bath are ideally suited to engines with high torque outputs like the direct-injection turbo-charged units of the new Mercedes-Benz A-Class. The clutches are activated and the gears shifted automatically without any interruption in power flow. The seven ratios of the 7G-DCT have been chosen to permit rapid acceleration from standstill with quiet, economical cruising.
The Mercedes-Benz 7G-DCT is more compact and lighter than comparable transmissions from other manufacturers, and is operated by a selector lever and shift paddles integrated into the steering wheel, a first for a compact family car. One of the clutches operates the odd-numbered gears and the other works the even-numbered gears so that the next gear is always primed ready to come into operation instantaneously and smoothly as needed, whether accelerating or braking.
Cruise Control and the Speedtronic variable speed limiter are included with the 7G-DCT automatic transmission in Sport, AMG Sport and Engineered by AMG models, along with the brake Hold function. All the driver needs to do is push the brake pedal slightly more firmly than usual and the car will remain held without the need to keep pressing the pedal down. The Hold function also restrains the car momentarily when setting off on steep gradients to prevent it rolling backwards.
Six-speed manual transmission
The standard transmission in the new A-Class is a new six-speed manual gearbox developed in conjunction with the 7G-DCT. They share a large number of components and are produced in the same Hedelfingen plant.
The six-speed manual transmission is, like the 7G-DCT, compact and light, and designed for satisfyingly quick and positive shifting. Lightweight, cast-aluminium shift forks are installed on anti-friction bearings on the shift rods to reduce the effort needed for gear changing. A wide spread of ratios ensures the new A-Class is particularly sprightly when setting off and yet is able to cruise quietly and economically at motorway speeds.
Safety
The Mercedes-Benz approach to safety exceeds any current global legislation. Naturally, the company ensures its cars can achieve a maximum safety rating in any test procedure in any country, but it also studies accidents that have actually happened involving its cars to see if there is anything that can be learned to improve their already exemplary protection. Mercedes-Benz calls this intelligence-gathering process 'Real Life Safety'.
It is this approach which has led Mercedes-Benz to develop the radar-based Collision Prevention Assist, fitted as standard to the new A-Class range. Mercedes-Benz tries first and foremost to ensure its cars are engineered to avoid accidents - which is why the A-Class is also fitted as standard with Attention Assist, Adaptive Brake Assist, anti-lock brakes (ABS) with Brake Assist (BAS), ESP® with Acceleration Skid Control (ASR).
But it also ensures they are among the safest cars on the road should the worst happen, so there are seven airbags, including a driver's knee bag, and an Active Bonnet to offer pedestrians further protection. The Pre-Safe® anticipatory crash protection is optionally available.
The Mercedes-Benz Emergency Call System is also standard in cars ordered with COMAND Online to alert the rescue services in the event of an accident, while options include the Lane Tracking Package consisting of Blind Spot Assist and Lane Keeping Assist, the multi-beam Intelligent Light System and Distronic Plus autonomous emergency braking.
The first line of defence: the body shell
The first line of defence is provided by the strength of the A-Class body itself. The new A-Class has sailed through Mercedes-Benz' rigorous programme of crash tests. This includes not only some 30 different impacts required for safety ratings and international type approval, but another nine crash tests, such as the roof-drop test or the pole impact test, developed by Mercedes-Benz.
The ability of the new Mercedes-Benz A-Class to satisfy requirements far beyond statutory standards is demonstrated by an internal offset front collision test. Despite the high impact speed, the A-Class passenger compartment remained intact.
The ability of the body shell to offer such a high standard of passive safety is down to the materials used - the proportion of high-strength and ultra-high-strength steels is 67 per cent - and its structural design. At the front end there is an impact absorption area of 435 mm to soak up crash loads, which are dissipated over several planes.
A total of three longitudinal sections - straight front longitudinal members, an upper plane of extruded aluminium box sections attached to the front end, and a third plane at the bottom in front of the subframe - allow impact energy to be reduced in a highly controlled manner.
The subframe provides the torque support for the transverse engine and transmission and is also used to secure the front axle and steering. It consists of several steel plates, some in ultra-high-strength steel, and a hydroformed tube. The subframe is connected via two aluminium struts leading forward to the aluminium radiator mount. In a frontal impact, forces can be discharged into the subframe early via this third load path to ensure the best possible energy dissipation.
A plastic crash wedge at the rear of the front wheel arches helps to ensure that the wheels do not slide under the front doors in a high-impact crash, so that it is still possible to open the doors.
The bulkhead also incorporates a special feature known as 'skate runners' to discharge forces into the floor. The continuous floor structure consists of a total of four straight longitudinal members. The tunnel roof reinforcements at front and rear combine with the tunnel to provide a further closed profile supporting the front end.
Rigid side structures and defined deformation management help to safeguard occupants against side impacts. Elements here include the pole support and a diagonal brace in the rear footwell, between the centre tunnel and floor side wall, which is intended to prevent the floor from being torn open in the event of side impact with a tree.
High-strength steels are used in the upper area of the B-pillar to minimise intrusion and to preserve the passenger cell in case of side impact. The lower area of the B-pillar is softer so that it dissipates energy better. The insides of the B-pillar contain what are referred to as 'vampire's teeth' to prevent cracking that could ensue if the seat belt retractor presses against the inner wall of the B-pillar.
The new A-Class features numerous measures designed to help lessen the risk of injury to pedestrians in the event of a collision. The deformation space between the bonnet and the components beneath it has been maximised by relocating items such as control units or fluid reservoirs in the engine compartment.
For the A-Class, with its sleek, low-slung body, there is also an active bonnet. In the event of a pedestrian impact, sophisticated sensors combined with intelligent algorithms trigger actuators around the bonnet hinges. These raise the bonnet by 65 millimetres. The additional space this creates between the bonnet and hard areas in the engine compartment means that a pedestrian's head is subject to comparatively low acceleration forces on impact.
Intelligent restraint systems
The A-Class protects occupants with seven airbags as standard, including a driver's knee bag. There are also driver and front-passenger airbags, large thorax-pelvis bags incorporated in the front seats and window bags which extend over both rows of seats to the A-pillar.
The driver and front-passenger airbags operate in two stages, according to the expected severity of the impact. The gas generator first fills the driver's airbag with 60 per cent gas and the front passenger's airbag with 70 per cent gas. If a more severe impact is forecast, the second stage of the gas generator will activate and the airbags will be filled at a higher pressure. Rear side bags are optionally available.
The deformable steering column yields by up to 100 mm when the driver exerts pressure on the airbag. The head restraints for the driver and front passenger are new developments to minimise the risk of whiplash injury. The key to effective whiplash prevention is to have the best possible distance between the head restraint and the head of the person in the seat. The restraint incorporates a button on the left-hand side to unlock the head restraint and increase the distance. The button does not need to be pressed to reduce the distance.
Rear-seat protection: planning ahead
The new A-Class meets the rear-seat protection requirements of the Japanese and Chinese NCAP institutes. This takes into account factors such as the ease of use of the belts, and Mercedes-Benz safety experts believe that Euro NCAP will soon extend its rating programme to include rear-seat safety.
The Mercedes-Benz A-Class is already prepared for this with features such as standard-fit belt tensioners and belt force limiters for the outer rear seats. A torsion bar in the roller mechanism twists when the load on it exceeds a defined level. In this way the belt force is limited and with it the load on the seat occupant. The A-Class has ISOFIX child seat mounting points on both outer rear seats. Child seats can additionally be fixed via special anchorage points with top tethers.
Pre-Safe®: anticipating accidents
Pre-Safe®, the Mercedes-Benz anticipatory occupant protection system which premiered in the S-Class of 2002, is available in the A-Class for the first time as part of the on-going policy to cascade advanced safety technology throughout the range. It uses the time between detection of a potential accident and a possible collision to initiate preventive protection measures, thus reducing the loads exerted on occupants if a crash occurs by up to 40 per cent.
Pre-Safe® tensions the seat belts, closes any open side windows (and the sunroof, if fitted) and adjusts the optional fully electric front passenger seat with memory function to an ideal position for maximum effectiveness of the restraint systems.
Pre-Safe® is activated in emergency or panic braking, if the ESP® system detects pronounced over- or understeer, if there are critical steering movements or if Brake Assist is required to provide additional braking support.
Automatic Emergency Call System
When ordered with the optional COMAND Online with Media Interface, the new A-Class is equipped with another safety feature to ensure occupants get help from the emergency services quickly and automatically: the Mercedes-Benz emergency call system. It functions as long as COMAND Online is connected to a mobile phone.
After the airbags or belt tensioners are triggered, the vehicle's GPS position and identification number (VIN) are sent by SMS to a special emergency centre. Positional data is also transmitted using the DTMF dual-tone multi-frequency method at the same time. Even if the occupants are unconscious or unsure of exactly where they are, the emergency services alerted by the emergency centre will be notified quickly with accurate information.
The driver can also make the emergency call manually as 'MB emergency call' is always the first entry in the system phone directory. On receiving the call, the emergency centre establishes voice contact with the vehicle occupants within seconds in the language which the driver has pre-set in COMAND Online. Other than any mobile phone communication charges, no costs are incurred by the driver and no additional phone contract is required to use this service.
Advanced range of driver assistance systems
The innovative radar-based Collision Prevention Assist heads a host of advanced driver assistance systems to be found in the new Mercedes-Benz A-Class. Collision Prevention Assist gives a visual and audible warning to a possibly distracted driver of the risk of a nose-to-tail accident. At the same time it prepares Brake Assist for full emergency braking regardless of the force exerted on the pedal by the driver.
Unlike other assistance systems in compact cars, Collision Prevention Assist does not merely minimise minor damage in low-speed accidents. Instead, it protects against rear-end collisions at speeds above 19 mph. Field tests carried out by Mercedes-Benz in Europe, North America, Japan and South Africa over a total distance of more than three million miles since 2005 confirm that the most critical rear-end collisions are at speeds above 19 mph.
Mercedes-Benz expects that the effect of Collision Prevention Assist will be similar to that which followed the introduction of ESP® as standard. Tests involving 110 drivers in the dynamic simulator saw the accident rate fall from 44 to 11 per cent in three typical scenarios thanks to the combination of collision warning and adaptive braking assistance. Mercedes-Benz safety experts believe Collision Prevention Assist can prevent around 20 per cent of all nose-to-tail collisions and reduce the severity of them in a further 25 per cent of cases.
Collision Prevention Assist can recognise when the A-Class is too close to the vehicle ahead at speeds between 19 and 155 mph and warn the driver visually and acoustically. It can also recognise when the gap is decreasing, detect stationary objects ahead at up to 45 mph and adapt the activation threshold for the warning and adaptive Brake Assist to given driving situations. It calculates the precise braking force needed to avoid an accident.
When the A-Class is equipped with Pre-Safe®, Collision Prevention Assist provides one of the activation parameters for the anticipatory safety systems.
Collision Prevention Assist works in conjunction with the standard-fit Adaptive Brake Assist system. If the driver abruptly releases the accelerator pedal - the first reaction in a potential emergency - Adaptive Brake Assist primes the brake pads so that they come into light contact with the brake discs. Should emergency braking then be required, the necessary braking pressure is achieved instantly. During wet weather it lightly but systematically applies brake contact to dry the brake discs.
The Mercedes-Benz Hold function is standard on all versions of the Mercedes-Benz A-Class. A slightly firmer push of the brake pedal after stopping holds the car without the driver having to maintain pressure on the brake pedal. It deactivates when the driver touches the accelerator. Hill-Start Assist is also standard on manual transmission models to ensure the car pulls away smoothly without rolling backwards, even on the steepest uphill gradient.
Attention Assist, the innovative system developed by Mercedes-Benz to monitor driver behaviour and warn of signs of tiredness, is another standard feature. During the first minutes of any journey, Attention Assist draws up a profile of the driver's individual style and then constantly compares subsequent behaviour with this accumulated data. It monitors more than 70 parameters, but is primarily based on steering wheel movements, since this is the first thing that becomes erratic when a driver is getting tired.
Continuous monitoring is crucial in detecting the gradual transition from alertness to drowsiness. In this way, the driver is given plenty of warning that it would be sensible to take a break. If Attention Assist detects signs of drowsiness, it issues an audible warning and flashes up a visual warning in the instrument cluster: Attention Assist Take a Break! It is active between 50 and 110 mph.
As options, the new A-Class can be ordered with the autonomous braking feature Distronic Plus, the Mercedes-Benz Intelligent Light System, a Lane Tracking Package which includes Blind Spot Assist and Lane Keeping Assist, and Active Park Assist with Parktronic automatic parking.
Distronic Plus
Distronic Plus adaptive cruise control is available on models fitted with the 7G-DCT seven-speed automatic gearbox. It delivers the twin benefits of enhanced safety in heavy traffic with the minimum of stress on the driver. Two short-range sensors behind the front bumper and a long-range sensor behind the radiator grille help to maintain a safe gap to the car in front by braking and accelerating the A-Class in response to the flow of traffic. It functions at speeds between zero and 125 mph. If it senses the gap to the car ahead is closing too quickly it issues visual and audible alerts.
Intelligent Light System
The optional Mercedes-Benz Intelligent Light System, incorporating bi-xenon headlights with LED daytime running lights, headlamp wash and LED tail lights, and Adaptive High Beam Assist with cornering light function that automatically varies the beam pattern and lighting according to where and how fast the A-Class is being driven.
It has five light functions - country mode, motorway mode, enhanced foglamps, active light function and cornering light.
Low beam is replaced by country road mode, which illuminates the side of the road more brightly than the centre. At speeds above 55 mph, motorway mode takes over, increasing the driver's range of vision by up to 60 per cent. At 68 mph the beam on the driver's side is elevated slightly. Motorway mode has a range of around 120 metres and is designed to increase the driver's range of vision by about 50 metres compared with conventional low-beam headlamps.
The enhanced foglamps are activated at speeds below 40 mph as soon as the rear foglamp is switched on. The bi-xenon headlamp on the driver's side of the car pivots by eight degrees and is lowered at the same time. This adjustment illuminates the centre section of the road more brightly and reduces glare from light reflected by the fog.
The active light and cornering light functions are switched on automatically, depending on the steering angle, rate of turn and vehicle speed. The active light function pivots the headlamps by up to 15 degrees almost instantaneously. It is activated automatically when the driver turns the steering wheel at speeds below 40 mph.
The Intelligent Light System includes Adaptive High Beam Assist, which constantly adjusts the range of the headlamps so as not to dazzle drivers of oncoming vehicles or vehicles in front of the A-Class. The Mercedes-Benz system uses graduated steps between dipped and main beam rather than a sudden adjustment, which means the driver enjoys the best possible visibility for more of the time.
Lane Tracking Package
The Lane Tracking Package is designed to prevent owners from straying into the path of other cars when changing lanes. It consists of Lane-Keeping Assist and Blind Spot Assist. Lane Keeping Assist reads the lane markings on the road and, if the A-Class crosses them unintentionally, it alerts the driver by gently vibrating the steering wheel. Blind Spot Assist uses two radar sensors to detect a vehicle approaching from behind. If the Mercedes-Benz A-Class driver attempts to pull out, it issues visual warnings in the door mirrors and an audible warning within the car. It functions at speeds above 30 mph.
Active Park Assist with Parktronic
Active Park Assist with Parktronic measures potential parking spaces through ultrasonic sensors in the front and rear bumpers. If the space is large enough for the car, the system operates the electro-mechanical power steering while the driver works the accelerator and brake.
Technology
The new A-Class is the second model in a totally new family of compact front-wheel-drive cars from Mercedes-Benz, following the introduction of the latest B-Class in 2011. Built around entirely new architecture, the new Mercedes-Benz compacts feature so many advances over their predecessors that they are virtually a moving catalogue of the company's current technology.
With outstanding aerodynamics, turbo-charged direct-injection engines across the range and the availability of a 7G-DCT double-clutch automatic gearbox on most models, the new Mercedes-Benz A-Class is packed with technology to improve efficiency.
The safety features are unmatched in any comparable compact car, and many have cascaded down from the company's larger luxury models. The new A-Class even includes in-car internet access. For the first time in any Mercedes-Benz, it will be possible to have full integration with the content of Apple iPhones, operable through the car's on-board central controller.
Aerodynamics
Countless flow simulation studies on computer and hours of fine tuning in the wind tunnel have resulted in a drag co-efficient, or Cd figure, of 0.27 for the new A-Class.
This was no easy task on a hatchback model with a short rear overhang. The detailed work which made it possible includes distinctive side spoilers next to the rear window ('finlets'); patented serrated wheel spoilers at the front and rear, slots in the wheel arches and optimised hubcaps which reduce flow losses; an adjustable radiator shutter which closes louvres behind the radiator grille when there is no need for cooling air; an aerodynamically enhanced underbody plus extensive cladding up to the rear wheel arch and around the rear axle; and exterior mirrors which have been shaped based on lessons learned with other recent Mercedes-Benz introductions, including the B-Class.
Active Park Assist with Parktronic
The new A-Class can measure its own parking spaces and steer itself in while the driver operates the accelerator, clutch and brake, thanks to the optional Active Park Assist with Parktronic ultrasound sensors. It operates at speeds below 20mph once reverse gear has been selected.
Adaptive Brake Assist
Adaptive Brake Assist, a feature which minimises stopping distances in emergencies, is standard on every version of the new A-Class. It comes into operation if the driver abruptly releases the accelerator pedal - usually the first reaction in a potential emergency. Adaptive Brake Assist primes the brake pads so that they come into light contact with the brake discs, which means that the necessary braking pressure is achieved instantly if an emergency stop becomes necessary. During wet weather it systematically applies brake contact to dry the brake discs.
Adaptive Brake Assist incorporates the Mercedes-Benz Hold function, which keeps the car stationary whenever it comes to rest without the driver having to keep a foot on the brake pedal. On manual transmission models there is a further convenience feature in the form of Hill Start Assist, which prevents the car rolling backwards on gradients as the driver's foot moves from the brake to the accelerator.
Attention Assist
This innovative system, developed by Mercedes-Benz to monitor driver behaviour and warn of signs of tiredness, is being added as standard to every new or upgraded model, and now appears in the Mercedes-Benz A-Class. The system monitors more than 70 parameters, but primarily focuses on steering wheel movements, since these are the first to become erratic when a driver is getting tired.
At the start of every journey, Attention Assist draws up a bespoke driver profile which is subsequently compared with the driver's later actions. If Attention Assist detects signs of drowsiness it issues audible and visual warnings advising the driver to take a rest.
BlueEFFICIENCY
BlueEFFICIENCY is the name that Mercedes-Benz gives to technologies which help to lower fuel consumption and emissions. In the new A-Class they start with the new highly-efficient direct-injection turbo-charged petrol and diesel engines and include the option of a 7G-DCT dual-clutch automatic gearbox on many models, standard ECO start/stop, intelligent alternator management to convert braking energy into electrical energy, intelligent management of the oil feed and water pump, a display to encourage more economical driving, low rolling resistance tyres and an adjustable radiator shutter.
Collision Prevention Assist
Collision Prevention Assist is a world-first feature exclusive to Mercedes-Benz and introduced with the latest B-Class. Now it is also included as standard in the A-Class. It is a radar-based system which can reduce the risk of nose-to-tail collisions, or minimise their effects, in conjunction with Adaptive Brake Assist. If the driver becomes distracted and there is a risk of a collision, Collision Prevention Assist issues visual and acoustic warnings while priming the Brake Assist function to ensure maximum stopping power as soon as the driver touches the brake pedal. Unlike some systems, which work only at urban speeds, Collision Prevention Assist functions at any speed above 19 mph.
COMAND Online with Media Interface
With the optional COMAND Online system, the new A-Class becomes a fully connected car with full internet access when stationary via a mobile phone. COMAND Online with Media Interface is the hub for a vast range of communications, entertainment and navigation services. As well as in-car internet access it includes a hard-drive navigation system, 10GB of storage space for a music library, speed-sensitive volume adjustment of the audio system and a DVD drive that plays CDs, MP3s or video and audio DVDs. It also allows a number of external devices and storage media to be connected via a USB port, a Media Interface, an SD card slot or Bluetooth®. Via the internet there is access to Mercedes-Benz online services. Integrated Mercedes-Benz apps include Google™ Local Search and Weather and the option of downloading a route pre-set on a home computer through Google™ Maps.
Direct-injection turbo-charged engines
Every engine in the new A-Class features direct injection and turbo-charging to promote the most efficient use of fuel with outstanding driveability. The petrol engines are new advanced four-cylinder 1.6-litre or 2.0-litre units, designed for either transverse or longitudinal installation, and will be featuring in several other Mercedes-Benz model series in the future. The diesels are new 1.6-litre, 1.8-litre and 2.2-litre units that offer excellent economy, performance and refinement levels.
Energy Space Architecture
Mercedes-Benz calls the structure on which the new Mercedes-Benz A-Class is based 'Energy Space Architecture'. It replaces the sandwich floor concept of the previous two generations and allows the seating positions to be lowered by 174 mm, which in turn brings about a 24 mm lower centre of gravity, contributing to the new car's more dynamic behaviour. It will also allow the main floor panel to be modified to accept alternative powertrains with just one extra stage in the production process.
ECO start/stop
Every new A-Class features ECO start/stop technology to reduce fuel consumption. By shutting down the engine when the car is stationary, no fuel is used and no emissions generated when the car is held up by traffic. In manual versions the engine switches off as soon as the driver applies the brakes, shifts the transmission lever into neutral and releases the clutch. The engine restarts as soon as the driver depresses the clutch. With the optional 7G-DCT dual-clutch automatic transmission, ECO start/stop deactivates the engine as soon as the vehicle is motionless and the driver presses the brake pedal. The engine restarts when the driver's foot is removed from the brake pedal or when the accelerator is pressed.
7G-DCT dual-clutch automatic transmission
The 7G-DCT dual-clutch automatic transmission which made its debut in the new B-Class is available in many versions of the A-Class. It delivers the comfort and convenience of a full automatic gearbox with the fuel economy of a manual. It incorporates three shift programmes - ECONOMY, SPORT and MANUAL. In ECONOMY and SPORT the gearshifts are fully automatic, while MANUAL mode hands full control to the driver. It incorporates two 'wet' multi-disc clutches running in an oil bath. One operates during selection of the 'odd' gears and the other works with the 'even' gears so that the next gear is always primed to come into operation instantaneously. The seven gears of the DCT transmission allow a wide spread of ratios for sharp acceleration from standstill and economical and relaxed motorway cruising.
Intelligent Light System
The Mercedes-Benz Intelligent Light System incorporating bi-xenon headlights with LED daytime running lights and tail lights, Adaptive High Beam Assist and cornering light function is an option with the new Mercedes-Benz A-Class. It features five light functions - country mode, motorway mode, enhanced fog lamps, active light function and cornering light function - for differing driving or weather conditions. Low beam is replaced by country road mode, which illuminates the side of the road more brightly than the centre. Above 55 mph, motorway mode takes over, increasing the driver's range of vision by up to 60 per cent. The enhanced fog lamps are activated at speeds below 40 mph as soon as the rear fog lamp is switched on, while the active light and cornering light functions switch on automatically, depending on the steering angle, rate of turn and vehicle speed. Also included is Adaptive High-beam Assist, which constantly adjusts the range of the headlights based on the distance of oncoming vehicles or those in front. The system uses graduated steps between dipped and main beam rather than a sudden adjustment, and is therefore more restful for the driver's eyes.
Lane Tracking Package
The optional Mercedes-Benz Lane Tracking Package is designed to prevent distracted drivers from straying into the path of other cars when changing lanes. It consists of Lane-Keeping Assist and Blind Spot Assist. Lane Keeping Assist reads the lane markings on the road and, if the car crosses them unintentionally, alerts the driver by gently vibrating the steering wheel. Blind Spot Assist uses two radar sensors to detect a vehicle approaching from behind. If the driver attempts to pull out to overtake, it issues visual warnings in the door mirrors and an audible warning within the car.
Pre-Safe
The Mercedes-Benz anticipatory safety system Pre-Safe® uses the ESP® Electronic Stability Programme sensors to recognise potentially dangerous situations and transmit the information to the car's electronic control units. It ensures the seat belts and airbags deploy with maximum effect in the event of a collision, and closes any open windows and the sunroof, if fitted. It also moves the front passenger's seat to the safest position if the car has been ordered with the Memory Pack. It is an option in the new Mercedes-Benz A-Class.
Technical Specifications
A 180 BlueEFFICIENCY: 1,595 cc petrol engine, 122 hp at 5,000 rpm, 200 Nm at 1,250-4,000 rpm, 0-62 mph in 9.2 seconds (9.1 seconds with 7G-DCT), top speed 126 mph, average fuel consumption 51.4 mpg (52.3 mpg with 7G-DCT), CO2 emissions 128-135 g/km (127-133 g/km with 7G-DCT).
A 200 BlueEFFICIENCY: 1,595 cc petrol engine, 156 hp at 5,300 rpm, 250 Nm at 1,250-4,000 rpm, 0-62 mph in 8.4 seconds (8.3 seconds with 7G-DCT), top speed 139 mph, average fuel consumption of 49.6 mpg (50.4 mpg with 7G-DCT), CO2 emissions 134-136 g/km (131-133 g/km with 7G-DCT).
A 250 BlueEFFICIENCY: 1,991 cc petrol engine, 211 hp at 5,500 rpm, 350 Nm at 1,200-4,000 rpm, 0-62 mph in 6.6 seconds, top speed 149 mph, average fuel consumption of 45.6 mpg, CO2 emissions 145 g/km.
A 180 CDI BlueEFFICIENCY 6-speed manual: 1,461 cc turbodiesel engine, 109 hp at 4,000 rpm, 260 Nm at 1,750-2,500 rpm, 0-62 mph in 11.3 seconds, top speed 118 mph, average fuel consumption of 74.3 mpg, CO2 emissions 98-105 g/km.
A 180 CDI BlueEFFICIENCY 7G-DCT seven-speed automatic: 1,796 cc turbodiesel engine, 109 hp at 3,200-4,600 rpm, 250 Nm at 1,400-2,800 rpm, 0-62 mph in 10.6 seconds, top speed 118 mph, average fuel consumption of 68.9 mpg, CO2 emissions 109-116 g/km.
A 200 CDI BlueEFFICIENCY: 1,796 cc turbodiesel engine, 136 hp at 3,600-4,400 rpm, 300 Nm at 1,600-3,000 rpm, 0-62 mph in 9.3 seconds (9.2 seconds 7G-DCT), top speed 130 mph, average fuel consumption of 62.8 mpg (65.7 mpg 7G-DCT), CO2 emissions 118-121 g/km (114-116 g/km 7G-DCT).
A 220 CDI BlueEFFICIENCY (7G-DCT only): 2,143 cc turbodiesel engine, 170 hp at 3,400-4,000 rpm, 350 Nm at 1,400-3,400 rpm, 0-62 mph in 8.2 seconds, top speed 137 mph, average fuel consumption of 64.2 mpg, CO2 emissions 115 g/km.
0 comments:
Post a Comment