Abstract: A motor vehicle cruise control system having an input for entering a desired vehicle speed. A vehicle speed deviation having a range both above and below the desired vehicle speed is entered. A memory at least temporarily saves a highway topography data set for a highway currently being traversed by a motor vehicle. A controller distinguishes an approaching highway topography change from a current highway topography condition using data from the highway topography data set; and calculates 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.

Abstract: In a motor vehicle power train including a fuel injected internal combustion engine and a hydraulic automatic transmission, an improved engine fueling control strategy for maintaining proper engine RPM in the presence of an automatic transmission Park or Neutral (P/N) to Drive or Reverse (D/R) range shifting. Communication between the Engine and Transmission Control Modules enables precise anticipation of rapid engine intake manifold absolute pressure (MAP) increases associated with P/N to D/R range shifting. Additional fuel is injected immediately preceding the MAP increase in order to maintain the proper engine air/fuel ratio necessary to prevent RPM sags and engine stalls during the clutch engagement. Once the clutch engagement is complete, the additional fuel is progressively eliminated.