A predictive cruise control system utilizes information about the current vehicle position, and upcoming terrain to save fuel and increase driving comfort. A vehicle operating cost function is defined, based on a plurality of environmental parameters, vehicle parameters, vehicle operating parameters and route parameters. As the vehicle travels over a particular route for which route parameters, such as road gradient and curvature, are stored in a road map, sensors aboard the vehicle detect environmental and vehicle operating parameters, including at least vehicle speed and its position relative to the road map. As the vehicle proceeds, an onboard computer iteratively calculates and stores in a memory vehicle control parameters that optimize the vehicle operating cost function for a predetermined prediction horizon along the route ahead of the vehicle. The optimal vehicle control parameters for the Prediction Horizon are then stored, updated and used to control the vehicle.