A method of controlling a hybrid vehicle with an engine, a battery, and at least one motor generator. System efficiencies of each of several candidate driving states are calculated. Calculating efficiency when the battery is discharged uses power of the engine Pfuel, power drawn from the battery Pb,out, and required driving power Pdemand. Calculating efficiency when the battery is charged uses Pfuel, Pdemand, and power charged to the battery Pb,in. Pb,out is calculated using a real battery discharge power Pb,out,real, a battery discharge energy efficiency ηbd, a historic efficiency ηb,pwr of energy loss when the battery is charged, and a correction coefficient SOCcorrection for controlling the battery charge amount. Pb,in is calculated using real battery charge power Pb,in,real, battery charge energy efficiency ηbc, ηbd, and efficiency ηin,pwr when power is consumed in the future. The driving state with the highest efficiency is then selected.