Kenworth is now offering the Cummins Westport ISX12 G heavy-duty natural gas engine for use in regional haul, vocational and refuse markets. This new engine requires a single fuel source and can run on either compressed or liquefied natural gas.

The ISX12 G will be available with the Kenworth T660, Kenworth T800, Kenworth T800 short hood, and the Kenworth W900S. The ISX12 G will come with a range of ratings to 400 horsepower and 1,450 pounds-feet of torque, optional engine brake and manual and automatic transmission capability to meet customer needs.

Kenworth already offers the 15-liter Westport HD and the 8.9-liter Cummins Westport ISL G as factory-installed options.

"The ISX12 G is a perfect size for the operational needs of those regional and refuse haulers that require a little more power and torque than offered by the ISL G, but that don't need as much as provided by the HD," says Andy Douglas, Kenworth national sales manager for specialty markets.

The natural gas engine uses a maintenance-free, three-way catalyst and does not require a diesel exhaust fluid tank, diesel particulate filter or selective catalytic reduction technology.

When the ISX12 G is launched next year, Cummins Westport expects it to be certified to meet the U.S. Environmental Protection Agency and California Air Resources Board emission standards of 0.20 g/bhp-hr NOx and 0.01 g/bhp-hr PM. The engine is also expected to be capable of meeting EURO VI and pending U.S. greenhouse gas and fuel economy regulations.