Mercedes-Benz Auto 2000 (1981)
Mercedes-Benz Auto 2000 research car – towards an economical, low-emission future.
V8 petrol engine with cylinder shut-off and bi-turbo diesel engine.
Pointing the way forwards for aerodynamics.
Despite its complicated wording, the project title nevertheless succeeded in firing the imagination: “Demonstration of automotive engineering research results in the form of integrated overall concepts for passenger car test models.” This was how the Federal Ministry for Research and Technology worded the call it made to German car manufacturers in 1980 to devise proposals for the passenger cars of the future. The primary objective was a reduction in fuel consumption: the target limit was 9.5 litres per 100 kilometres for cars with a kerb weight of between 1250 and 1700 kilograms and 11 litres per 100 kilometres for kerb weights up to 2150 kilograms.
The cars also had to be able to accommodate at least four persons and carry a payload of over 400 kilograms, all without comprising in any way on performance, comfort or range. Clear improvements were also expected in terms of service life, ease of repair, safety and environmental compatibility compared to series-production cars of that time.
Manufacturers had until spring 1981 to prepare road-worthy prototypes of their visions for the future, which would then be unveiled to the public in September of the same year. The Federal Ministry for Research funded this ambitious project to the tune of around 110 million Deutschmarks, a figure which was then matched by the German automotive industry. Economy, preservation of resources, reduction of emissions – all challenges to mainly test the skills of drive system researchers. Mercedes-Benz soon had two new engine concepts ready to try out in the new “Auto 2000” research car.
Despite being built around quite different technologies, the two powerplants still had one thing in common: their rated output of 110 kW/150 hp, which was deemed to be adequate at the time in view of the lightweight, streamlined body with its Cd value of just 0.28.
The petrol engine designed for the research car was derived from a standard V8 powerplant with a displacement of 3.8 liters. What made the modified engine so special was its fuel consumption, which was significantly lower at partial throttle. The key to achieving this was an automatic cylinder shut-off system that temporarily shut down four of the eight combustion chambers whenever the extra power was surplus to requirements. The fact is that four cylinders operating at full load consume less fuel than twice as many cylinders operating at partial load, resulting in the fuel consumption figure for the Euromix driving cycle (urban, 90 km/h and 120 km/h) being reduced to just 9.3 liters per 100 kilometers.