First look: Mercedes-Benz B-class is a gas

MERCEDES-BENZ will introduce a revised B-class model in Australia in the third quarter of this year, with facelifted styling as well as technical refinements and innovations.

Revealed in Stuttgart late last week, the facelifted small car sports a bold new metallic-finish three-bar grille and lower bumper that is in keeping with the latest trend in Benz styling and results in a distinctly sporty, almost AMG look.

This sportier look is enhanced by making body coloured wing mirrors, door handles and side skirts body standard across the range while Mercedes says the new front end was designed to make the car look wider than before.

Mechanically, the big news is the introduction of a new bi-fuel model called the B170 BlueEfficiency, which runs on premium petrol or natural gas. Using either fuel, the four-cylinder engine develops 85kW of power.

There are five onboard gas reservoirs with a total capacity of 16kg located under the front passenger footwell and in the boot, providing a range of more than 300km in addition to the 700km range running on petrol. The cylinders reduce boot space by 128 litres to 422 litres.

The driver selects which power source the engine is run on with a button located on the multifunction steering wheel and can be done on the move without any hesitation or change in performance.

Mercedes engineers modified the engine to include additional gas injectors on the underside of the intake manifold. A close-coupled pressure governor with an electromagnetic shut-off valve regulates the supply of natural gas and keeps the pressure within the system constant.

The company claims that the cost of running the B170 on natural gas is around 50 per cent less than when running on petrol while the overall CO2 emissions are 17 per cent lower than the petrol-powered B170.

The new B170 NGT (Natural Gas Technology) model will be officially launched onto the European market later this year. Mercedes-Benz Australia has yet to finalise its revised model line-up and specifications.

Benz is also introducing an optional stop/start function that switches the engine off at traffic lights, helping to reduce fuel consumption (by up to nine per cent) and emissions. The engine instantly restarts when the clutch is pressed or the brake pedal released, thanks to a starter-generator connected by a belt to the crankshaft, allowing the engine to start much faster and far more quietly than with the conventional starter. While driving, the starter-generator feeds the electrical system with energy.

The company claims its improved engines now undercut the current European Union emissions standards by up to 90 per cent.

Other technical changes include an automatic hill-start assist function (built into the standard ESC system) that stops the car from rolling backwards, plus the introduction of an optional active parking assist system.

The park assist function uses ultrasonic sensors at the sides of the car to assess potential parking spaces and then reverse parks the car without the driver having to steer. It is claimed to be so accurate that the parking space needs to be only 1.3 metres longer than the car.

Although the interior is little changed, the steering wheel does now feature reach adjustment.

Meanwhile, TERRY MARTIN reports that Mercedes-Benz has just completed winter testing in northern Sweden with a B-class with fuel-cell drive.

The test program was held at double-digit below-zero temperatures and studied cold-start behaviour at minus 25 degrees Celsius, for example.

Engineers also looked at roadholding – specifically, adapting the electronic stability control system to the special requirements of a fuel-cell vehicle (as an electric motor exhibits different speed-governing behaviour to that of standard combustion engines).

Mercedes will launch the first small-series production of the B-class FCV early in 2010. It will feature a new generation of fuel-cell drive, offering higher performance – the electric motor develops 110kW and 320 Nm – and more compact packaging.

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