17^th October, 2000

4-cylinder models get new supercharged engines

Mercedes-Benz has introduced its more powerful supercharged four-cylinder engine to the coupe and cabriolet versions of the successful CLK model range, the SLK roadster and C-class (S202) wagon.

The new CLK 200 Kompressor, SLK 200 Kompressor, and C 200 Kompressor wagon models are powered by the 2.0-litre engine, with belt-driven supercharger, which delivers 120 kW and provides its maximum torque of 230 Newton metres from 2500 right up to 4800 rpm. This is the equivalent of a 21 per cent increase compared with the naturally aspirated engine that it replaces.

Mercedes-Benz premiered the high technology, high-efficiency four-cylinder unit in Australia earlier this year in the E-class.

The CLK 200 Kompressor now accelerates from rest to 100 km/h in 9.5 seconds (cabriolet: 10.5 seconds) and is content with 9.3 litres per 100 kilometres (NEDC overall average; cabriolet: 9.4 litres).

Even better performance is provided by the CLK 230 Kompressor with the modified 2.3-litre engine, which now delivers 145 kW and develops a maximum torque of 280 Newton-metres available from 2500 rpm. The coupe takes 7.9 seconds to accelerate from rest to 100 km/h (cabriolet: 8.6 seconds).

With these specifications the CLK 230 Kompressor has the performance level of a 6-cylinder model whilst maintaining an economical fuel consumption of 9.6 litres per 100 kilometres (overall average for both coupe and cabriolet in the New European Driving Cycle – NEDC).

Thanks to supercharging, the SLK 200 Kompressor with 6-speed manual transmission now accelerates from 0 to 100 km/h in just 8.2 seconds and consumes only 9.6 litres of fuel per 100 km (NEDC).

With its new engine, the C 200 Kompressor wagon is capable of sprinting from rest to 100 km/h in just 9.8 seconds. The fuel consumption amounts to 9.5 litres per 100 kilometres (NEDC overall consumption) matching that of the outgoing
C 200 despite the higher performance.

More than 150 engine components optimised
The basis of both power units is the proven Mercedes 4-cylinder engine that is also used in other model ranges.

Mercedes engineers have improved these engines with a view to future exhaust and noise emission limits, optimising more than 150 of their components. These include the cylinder heads, which now have oval-section inlet and outlet ports with optimised flow characteristics. This design improves the volumetric efficiency. The same purpose is served by a new, more compact combustion chamber design, which also reduces heat loss and therefore improves the response of the catalytic converter.

The camshaft of the 4-cylinder engines is equipped with a special Hall sensor that determines the position of the piston in the first cylinder on cold starting, thereby enabling better actuation of the relevant injectors. Starting performance of the cold engine is considerably improved by this system.

Another new feature is the electric suction-type fan that supplies the engine with cooling air and can be controlled according to actual need, thereby helping to reduce fuel consumption and noise emission. The air ducts and inlet manifold have been modified to provide better acoustic comfort, and a cover over the inlet manifold further reduces noise emissions.