Engine Transmission Matching

A study has been carried out, aimed at improving passenger car economy by better matching of the engine and transmission. Vehicle simulation was carried out which showed that a reduction of 25% in fuel consumed is theoretically possible. Engine development was carried out which showed that the results of valve timing changes were small, but the four valve cylinder head tested gave better economy than the two valve cylinder head over the whole engine operating range. Resulting from a study of transmissions, it is recommended that two wide span transmissions be developed - a six speed semi automatic and an eight speed fully automatic.