An Analytical Study of Transmission Modifications as Related to Vehicle Performance and Economy

A method of vehicle performance measurement has been developed so that selection of optimum fuel-economy-performance trade-offs can be made for a vehicle having various powertrain components. This method was utilized in an analytical study of drivetrain component features such as--overall ratio range, number of ratio steps, locked converters, continuously variable drives, etc. Both manual and automatic type transmissions are considered. Indications are that ratio range is an important consideration in the selection of transmission design parameters and also conventional transmission concepts can be competitive with the more exotic continuously variable type units.