The largest truckload company in the U.S., Knight-Swift, says it’s encouraged by the performance of the new Cummins X15N natural gas engine it is testing using renewable natural gas (RNG).

“Our customers rely on us to deliver a wide range of loads critical to their businesses,” said Dave Williams, Knight-Swift Transportation’s senior vice-president of equipment and government relations. “We must ensure we are utilizing the most reliable and efficient technologies possible that help us reduce our carbon footprint. We value our collaboration with Cummins and are encouraged by what we have seen so far with the 15L renewable natural gas technology.”

Knight-Swift aims to reduce its fleet’s CO2 emissions by 50% by 2035. Cummins is bringing the X15N to market next year, promising diesel-like performance and reliability while slashing emissions. RNG has won a fan in Arizona Congresswoman Debbie Lasko, who sa,id “Renewable natural gas is something we can utilize now with very measurable benefits to both the environment and the economy. This investment will help Arizona truckers adopt low-cost advanced technology.”

Field testing with Knight-Swift is slated to continue through full production in 2024.