A fuel system and powertrain for a flexible fuel system vehicle utilizes a
controller system to control variables in an engine and the final drive
optimize operating efficiency of the vehicle while using an
alcohol-gasoline blend. The controller system regulates engine operating
variables such as fuel pressure, fuel flow, air-fuel flow, air-fuel
temperature, and valve timing. The controller system regulates engine
operating variables such as transmission gear selection and gear changing
as well as differential ratio changes.