FUEL ECONOMY EFFECTS AND INCREMENTAL COST, WEIGHT, AND LEADTIME IMPACTS OF EMPLOYING A CONTINUOUSLY VARIABLE TRANSMISSION (CVT) IN MID-SIZE PASSENGER CARS OR COMPACT LIGHT TRUCKS

This report is a paper study of the fuel economy benefits on the Environmental Protection Agency (EPA) City and Highway Cycles of using a continuously variable transmission (CVT) in a 3625 lb (1644 kg) car and compact light truck. The baseline vehicles are viewed as being equipped with contemporary four-speed automatic transmissions with lock-up torque converters (4SAT). The engines are each three liters in displacement, four valves per cylinder for the car and two valves for the truck, each with sequential port fuel injection and electronic throttle control. The CVT selected for the study was a modified Van Doorne push belt type, termed the Dual Mode. Calculations were made for a range of CVT efficiencies: same, +3% and +6% relative to the 4SAT. This range was thought to cover practical designs for larger vehicles. For the car only, the camshaft was modified to provide increased torque at low speeds, the HITORC engine. For the car, Combined Cycle economy gains ranged from 6.6% with equal to 11.0% with an assumed 6% transmission efficiency gain. Gains for the light truck were very similar; 6.0% to 10.8%.