A system and method of controlling the operation of a transmission using fuel consumption data. The system and method includes controlling the operation of a vehicle transmission which is operatively connected to an engine and to a transmission control module having access to a memory. Fuel consumption data for a plurality of engines is converted to engine efficiency loss data representative of the each of the engines' operation. The plurality of patterns, each representative of the operating characteristics of one of plurality of engines, is stored in the memory. Engine operating characteristics are recorded during operation of the vehicle. One of the pluralities of patterns is selected based on the recorded operating characteristics to operate the vehicle in a fuel efficient manner.