NOVELTY - The method involves storing (304) vehicle operation data for a known route segment or a known route in a memory. A processor connected to the memory and to an engine of the vehicle is provided. The vehicle can travel over the known route segment or the known route is determined using the processor. An operation of the engine is adjusted based on the stored vehicle operation data for optimizing the energy efficiency of the vehicle.    USE - Method for optimizing energy efficiency of vehicle e.g. alternative fuel vehicle, hybrid electric vehicle, plug-in hybrid electric vehicle, electric vehicle or solar powered vehicle for known route segments or routes.    ADVANTAGE - The processor can efficiently balance the power utilized from the engine and the power utilized from the battery based on the current state of the vehicle and historical data of the predicted routes. The preceding steps can be eliminated to reduce the amount of data stored, simplify the processing of data for prediction and simplify the control operations for enhancing energy efficiency. The driver is allowed to improve driving habits to optimize energy efficiency because the inefficiency for warming up the engine could be avoided. The stored information about the route segment, route and/or route set can help the processor decide how much to draw from the battery and how much energy to draw from the engine based on historical data.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a system for optimizing energy efficiency of a vehicle for known route segments or routes.    DESCRIPTION OF DRAWING(S) - The drawing shows a control logic block diagram of the method of adjusting a vehicle operation based on predicted route segments.    Step for storing vehicle operation data regarding route segment (304)    Step for predicting a route segment for the vehicle (312)    Step for retrieving and determining vehicle operation data for the predicted route segment (314)    Step for adjusting start/stop threshold (318)    Step for adjusting power output using battery and/or engine (320)