Field Experience And Further Developments Of Control Systems For CVT's In Passenger Cars

After many years of joint development with Van Doorne's Transmissie BV, FORD has put a modern continuously variable transmission (CTX) for small FWD passenger cars in the market-place. Since May 1987 the CTX is offered in the 1.1 ltr. Fiesta as a low-volume pilot program. The very encouraging customer acceptance has strengthened FORD plans to launch high-volume production of the CTX for 1.1 ltr. Fiesta up to 1.6 ltr. Escort applications in foreseeable future.

The CTX also forms the base for further CVT-developments, covering larger vehicles, bigger engines and electronic controls.

The first part of this paper deals with initial field experience of the hydraulically controlled CTX in regard to driveability, comfort, performance and fuel economy. In the second part, improved control systems to fully utilize the potential of CVT's are described, including integrated powertrain management concepts.