Peterbilt Motors introduced two new medium-duty vehicles powered by compressed natural gas (CNG) during the Mid-America Trucking Show: the Model 337 and the Model 348. Both vehicles are now in production and can be configured as trucks or tractors. The company also announced that heavy-duty models 579 and 567 are now available with liquefied natural gas (LNG); Peterbilt had begun production of CNG configurations of the 579 and 567 last year.
Both the Models 348 and 337 are powered by the Cummins Westport ISL-G with 320 horsepower (239 kW) and 1,000 lb-ft (1,356 N·m) of torque. The engine complies with EPA 2010, 2013 and CARB emissions regulations.
The Models 579 and 567 LNG configurations are available as daycabs and production is scheduled for June. Both trucks are powered by the Cummins-Westport ISX12 G with up to 400 horsepower (298 kW) and 1,450 lb-ft (1,966 N·m) of torque.