XL Hybrids has begun supplying its XL3 gasoline-electric hybrid powertrain for General Motors' 3500/4500 cutaway and cab chassis van beginning with 2011 model-year vehicles, according to the company.

The XL3 Hybrid Electric Drive System is compatible with various wheelbases, including the GM cutaway single and double rear wheels. It can be installed as a retrofit or a new upfit for 4.8L and 6.0L gas engines, and it provides 20-percent fuel and carbon-dioxide savings, according to the company.

Upon installation of the XL3, GM's factory warranty remains intact, while the XL3 hybrid powertrain components are covered by a three-year, 75,000-mile warranty.

XL Hybrids' system saves fuel through regenerative braking, a process where the electric motor helps slow the vehicle when the driver brakes and charges the battery. When the driver accelerates, the battery releases the energy to the electric motor to propel the vehicle.