THE PORSCHE 995 RESEARCH CAR POWERTRAIN--A CONTRIBUTION TO REDUCING FUEL CONSUMPTION

The Research Car Study had an appreciable reduction in fuel consumption as a main objective. Fuel economy strategies included reduced vehicle weight and aerodynamic drag, minimization of parasitic losses (e.g. by low-friction drive shafts), improved energy efficiency measures, improved power transmission, and powertrain operation in the range of maximum efficiency. Results to date demonstrate the influence of engine displacement, fuel consumption during idling, and required driving performance on overall fuel economy. Analysis of fuel economy made with different engine concepts (Otto/Diesel, different number of cylinders, turbocharging, reduced idling fuel consumption) led to two engine variants for further study (four-cylinder and eight-cylinder with partial cylinder cutoff). Comparison of several transmission variants (e.g. hydrodynamic torque converter) showed that an automatic mechanical five-speed transmission with double clutch action was the most favorable solution. A central electronic system is to be installed for ignition, fuel injection, and transmission control as well as other duties (e.g. central information system).