A Sports Utility Vehicle from General Motors as innovation platform

General Motors considers hybrid technology a key technology for lowering fuel consumption and pollutant emission. The pick-up models GMC Sierra and Chevrolet Silverado were thus conceived as the first mild hybrid vehicles equipped with the 42V hybrid system worldwide. Series production for the hybrid system for these vehicles has been up and running now since the autumn of 2003.

Both vehicles are equipped with a V8-5,4l internal-combustion engine and automatic transmission. The mild hybrid vehicles will have noticeably improved fuel consumption. The vehicle types to be equipped with hybrid systems were chosen based on the potential to transfer the technology to other models of this high-volume platform at low cost. The primary objective during design and development of these vehicles was to reduce fuel consumption by 10-15% with as little deviation from the series standard as possible, also the presentation of improved utility for the customer through the 120V/240V power outlet of the hybrid system.

The damping function of the hybrid system played an important role in the successful realization of the development specifications both for integrating the hybrid system in the powertrain and for achieving the fuel consumption goals. It allowed not only for the reduction in size of the torque converter that led to the especially compact integration in the rotor of the electric motor, but also reduced the hydrodynamic losses in the torque converter and improved the functioning of the throttle cutoff. Great care was taken to design the startup of the internal combustion engine to function so rapidly and softly that it is not perceivable to the driver.