Abstract: A variable power drivetrain engine control system for a heavy duty vehicle such as a tractor/trailer combination or truck is disclosed. The engine control system provides higher output capability for the engine of the vehicle in accordance with certain detected conditions. If the vehicle speed falls a predetermined DELTA miles/hour below a LEARNED SPEED of the vehicle, the engine is enabled to operate at a higher power output capability until the vehicle resumes the LEARNED SPEED. Further, high output capability is enabled when the vehicle deceleration is in excess of a predetermined deceleration rate. Again, the high output capability is disabled once the vehicle retains the LEARNED SPEED velocity. The quantity DELTA can be variable with respect to actual vehicle speed to provide more responsive operation of the variable power drivetrain system thereby providing improved responsiveness to road conditions in accordance with relative vehicle speed.

Abstract: A method of operating a vehicle engine equipped with a cruise control includes the step of operating the engine in accordance with fuel delivery limits within a first range of delivery limits when the speed of the vehicle is less than a first speed limit and the cruise control is engaged such that the engine is controlled to permit acceleration of the vehicle under substantially all operating conditions. The engine is operated in accordance with fuel delivery limits within a second range of delivery limits less than the first range of delivery limits when the speed of the vehicle is greater than the first speed limit but less than a second speed limit. The engine is operated in accordance with fuel delivery limits within a third range of delivery limits less than the second range of delivery limits when the speed of the vehicle is greater than the second speed limit whereby the engine is controlled to permit acceleration of the vehicle under less than substantially all operating conditions thereof.

Abstract: A shift prompter/driver information display for a highway truck is disclosed. The display is operable to cruising, prompting, and shifting modes of operation. In the cruising mode of operation the driver of the vehicle can select, via a set of keypad switches, information about the vehicle's operation that he desires to see presented on a multi-digit decimal readout of the display. Information concerning fuel economy, engine speed, vehicle speed, travel time, travel distance and engine hours can be selected. In the prompting mode of operation the display indicates that operation of the transmission to a different gear is appropriate. The shifting mode commences when the driver initiates a shift to a different gear. In the shifting mode the target gear to which the transmission should be shifted is presented on the display.

Abstract: A passive mechanical damping system, particularly for the suspension of a cab from a truck frame, provides a minimal level of damping force to impede the free movement of a truck cab about its nominal height and also provides higher levels, progressively or in discrete steps, of damping as the movement of the cab exceeds preset limits of displacement defined by a lost motion connection to provide maximum vibration isolation while providing additional damping to control cab movement when the preset displacement limits are exceeded. The system provides a low rate viscous damper continuously connected between the cab and the truck frame and a high rate viscous damper connected therebetween through a lost motion connection.

Abstract: A control for and method of operating a vehicle engine (12) equipped with a cruise control (44) includes apparatus for and the steps of providing a memory (86) having stored therein first and second sets of data which control the position of a fuel rack (20) as a function of engine speed, determining when the cruise control (44) is engaged, retrieving the first set of data from the memory (86) when the cruise control (44) is engaged, retrieving the second set of data from the memory (86) when the cruise control (44) is not engaged and using the retrieved set of data to control the rate of fuel delivery to the engine (12) whereby extra power is available when the cruise control (44) is engaged to minimize downshifting. Also, fuel economy is improved and the set cruise control speed is better maintained.