November 5, 2012 10:00 AM, EST

FedEx Freight Testing LNG Tractors

FedEx Freight said it has begun testing two tractors powered by liquefied natural gas.

The two trucks, built by Kenworth Truck Co., use Cummins Westport’s ISX12 G engine, a FedEx spokeswoman said.

The pre-production engine, slated for limited release in 2013, “is currently the only all natural gas engine that begins to meet the size and power needs of Class 8 trucks,” FedEx Freight said in a statement.

Based at the company’s Dallas service center, the trucks are expected to drive close to 1,000 miles per day to test the engine’s ability to meet the demands of day-to-day operations.

FedEx Freight is the less-than-truckload unit of FedEx Corp. which is ranked No. 2 on the Transport Topics 100 listing of U.S. and Canadian for-hire carriers.