Optimized fuel economy during cruise control using topography data

A motor vehicle cruise control system, comprising:

• an input for entering a desired vehicle speed;
• an input for entering a vehicle speed deviation having a range both above and below the desired vehicle speed;
• a memory at least temporarily saving a highway topography data set for a highway currently being traversed by a motor vehicle;
• and
• a controller acting to:
• distinguish an approaching highway topography change from a current highway topography condition using data from the highway topography data set;
• and
• calculate a modified vehicle speed having increased fuel economy for traversing the highway topography change compared to a fuel economy at a selected vehicle speed for the current highway topography condition and to change the vehicle speed to the modified vehicle speed having the increased fuel economy prior to reaching the upcoming highway topography change.

A method for using a cruise control system for improving energy efficient operation of a motor vehicle, comprising:

• inputting a desired vehicle speed;
• entering a vehicle speed deviation having a range both above and below the desired vehicle speed;
• saving in a memory a highway topography data set for a highway currently being traversed by a motor vehicle;
• actuating a controller to distinguish an approaching highway topography change from a current highway topography condition using data from the highway topography data set;
• calculating a modified vehicle speed having increased fuel economy for traversing the highway topography change compared to a fuel economy at a selected vehicle speed for the current highway topography condition;
• and
• changing the vehicle speed to the modified vehicle speed having the increased fuel economy prior to reaching the upcoming highway topography change.