Fuel consumption and emissions are reduced through the use of an engine/transmission management system, which prevents unnecessary engine operation. The system is described on a subcompact car with Diesel engine and economy manual transmission. During vehicle deceleration and idle modes (accelerator pedal not depressed) power transmission from the engine is interrupted and the engine is shut off.
The engine is operating and power transmission to the wheels is provided only when driving force is required that means when the transmission is in gear and the accelerator pedal is depressed.
The interruption and the engagement of power transmission is accomplished by an automatic clutch actuator.
Monitoring and control of all system functions is accomplished by a microprocessor.