A Microprocessor Controlled Overdrive for Optimisation of Fuel Consumption 820391

This paper discusses a micro-processor controlled overdrive unit: which can be added, with suitable adaption to a standard 3/4 speed manual or automatic gearbox. The microprocessor either self contained or via an engine management system, uses signals of torque and speed at the overdrive to decide the optimum condition for overdrive selection on all forward gears, to give maximum fuel savings and acceptable driveability. Theoretical and practical fuel consumption figures, to the EPA schedule, show considerable fuel savings, particularly on the urban cycle where, it is concluded, overdrive will be selected under all moving conditions. As a fuel saving concept the system is unique giving performance and economy in a single package without intervention from the driver, except in respect of his driving habit.