Abstract: A method and system that utilizes the energy storage provided by a vehicle's mass in the form of potential and kinetic energy to optimize the fuel consumption. The system of the present invention is composed of an elevation database, a localization mechanism, and a speed optimization mechanism/engine. The optimization engine receives a desired speed range from the operator such as a max speed and min speed input, and a route or elevation profile form the elevation database. Then, utilizing the elevation database, the localization mechanism and a weight estimate the system and method optimizes the current speed to minimize fuel consumption by way of setting and adjusting the cruise control speed. The route and the weight estimate may be provided or predicted by the optimization engine.