At the Frankfurt International Motor Show in September 2011 Mercedes-Benz presented their new B-Class. The car is more aerodynamic as ever, and is now even more efficient and frugal with a whole range of brand new petrol and Diesel engines. On top of this come new transmissions, whereby we must admit that we drove the manual 6-speed version. But the new petrol engines are interesting enough, and we took the “base” 1,6 litre 90 kW engine through its paces. Here are our impressions of this car, which is the first of five models based on an all-new platform.
Hans Knol ten Bensel
The B-Class kept its characteristic and quite pleasing lines, which underline very well the personality of the model.
Nothing short of astonishing are the outstanding aerodynamic qualities of the car: it attains a drag coefficient of 0,24, which makes the car not only (very) fast, but also quite frugal on (fast) Autobahnen drives.
The oldest car manufacturer in the world really went to great lengths when optimising the aerodynamics: they perfected further the air flow around the front wheels, redesigned the underbody and improved the cooling air flow. New grounds were entered with for example a serrated wheel arch spoiler.
We also liked very much the new interior, its styling, its ergonomics, the quality of the materials used, the new, somewhat more upright seating position. Thankfully Mercedes maintains now the great looking round dials for speedometer and rev counter. We believe that no quality car should come without it. The ventilation orifices and openings have become typical for the marque, and we like them. The finish of the interior was also beyond reproach on our test car. The new interior is a success indeed.
A very smooth engine…
In this test we focused on the new engine. It is nice to know that all the new transmissions and engines have been developed in-house, with production taking place at the plants in Stuttgart-Untertürkheim, Stuttgart-Hedelfingen, Rastatt/Baden, Gaggenau/Baden and Kölleda/Thuringia.
The simultaneous development process enabled perfect coordination of engines and transmissions, e.g. with regard to implementation of the ECO start/stop function which is a standard feature on all B-Class models. Keeping all the development in house has its advantages: it enhances the capacity for making further improvements.
Upon starting the engine we were impressed by its silence and uncanny smoothness. The unit is also beautifully flexible, and will pull indeed from very low revs. It certainly allows very economical low-speed town and city driving, by staying in these very low rev ranges. Also the drivetrain and transmission behaves very well in these circumstances. The maximum torque of 200 Nm is already available from an engine speed of 1250 rpm right up to 4000 rpm.
The engine will readily rev (much) higher, without losing any of its smoothness. It develops its maximum power at 5000 rpm.
The combustion process is based on the third-generation Mercedes-Benz direct injection system which was introduced last year with the BlueDIRECT V6 and V8 engines.
The engine construction is indeed state-of-the art, with direct injection using fast-acting piezo injectors for multiple injection, controlled oil pump, switchable water pump, high compression (10.3:1) despite turbocharging, fast and convenient start/stop system – the technical details of the new generation of four-cylinder petrol engines
The only drawback we found, when driving in theECOmode, was the somewhat hesitant pick up when depressing the throttle at low revs. This made it very difficult to accelerate the car smoothly in slow city traffic. Whether it was a fault of our test car remains unanswered until know, we would have to test another example.
We would take the occasion to drive then the somewhat more powerful version, the B 200 which has an output of 115 kW (156 hp). But even with the “base” engine, the car will sprint from 0 to 100 km in 10,4 seconds and clock a top speed of 190 km. We were able to stay with our fuel consumption around the 6 litre/100 km range, which corresponds with the factory data. The combined CO2 emissions are given at 137 g/km.
With a pleasant manual transmission
We tested the 6 speed manual transmission, and it proved very smooth with quite effortless gearchanges. The box is designed as a three-shaft transmission and is technically indeed a close relative of the new 7G-DCT dual clutch transmission. We are very keen to put the latter through its paces in a following test…
The hallmarks of the new manual box are low shift forces and low internal friction…
Good road manners and roominess…
With the new chassis and suspension, a new electromechanical steering and improved stability control system, the car holds the road very well indeed. The rear suspension with an all new four-link rear axle feels still rather firm, but nevertheless the car offers good creature comfort.
The centre of gravity of the car is also lowered.
Mercedes-Benz is deploying the latestESP® generation in the B-Class for the first time. Torque Vectoring Brake helps to counter the tendency towards oversteering during fast cornering. Specific steering impulses assist the driver. The engineers' overall aim has been to provide gentle intervention by theESP® system which will afford the B-Class's occupants protection whenever possible, without detracting from the pleasures of driving: experienced motorists can indeed drive with verve, while less experienced drivers with a less well-rounded driving style will be reminded of the physical limits involved in driving.
The side mirrors are also aerodynamically optimized...
The new B-Class scores very well in terms of interior space. The rear seat can be folded downward and the car then offers very creditable loading space of 1547 litres. But even with the seats upright the space is a very creditable 488 litres. Plenty of space in the front door for bottles, and even the glove compartment box offers plenty of room. The front ad rear seats are well upholstered, offer good support and are comfortable. There is also very good leg- and headroom front and rear.
A car to have? Certainly if you like build quality and workmanship, and the unique personality of the marque. The new engine is wonderfully smooth, the interior is vastly improved and the car offers plenty of room and comfort, so you should certainly consider it…
Hans Knol ten Bensel
The BlueEfficiency label says it all: state of the art technology is under the bonnet.
The seats are very well upholstered and offer excellent support