Qualitative and Quantitative Influence of a Fully Electronically Controlled CVT on Fuel Economy and Vehicle Performance

The trend towards increased individualism concerning the car's response to drivers' preferences is evident. In combination with the desire for high performance plus severe legal requirements on fuel consumption and emission levels this sets the powertrain engineer an almost impossible task. A Continuously Variable Transmission with full electronic control offers an opportunity to meet this challenge due to its infinite number of ratios within a wide ratio span.

Based on the experience with 600000 CVT-cars in the field equipped with the VDT-belt a 250 Nm-CVT has been developed. This up-range CVT model features electronic controls for ratio and line pressure control, a torque convertor with lock-up and flow controlled pump. The transmission has been fitted to a 3, 3 I Chrysler Voyager. Fuel consumption measurements show a 17 % decrease in the ECE-cycle compared with the 4-speed automatic in one and the same car while improving the acceleration performance in the 0−100 km/h (0 − 62 mph) run by 1 second.