Arizona-based Knight Transportation, part of Knight-Swift Transportation Holdings, has been testing Cummins’ new X15N natural gas engine in Southern California. The truck is fueled by ultra-low carbon renewable natural gas (RNG) by Clean Energy’s station in Carson, California.

The field testing with Knight-Swift will continue through full production of the X15N powertrain in 2024. Knight Swift’s goal is to reduce CO2 emissions generated from the KNX fleet by 50% by 2035.

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

Coming to market in 2024, the Cummins X15N natural gas engine is expected to deliver diesel-like ratings, durability, and reliability to allow fleets to significantly reduce their carbon footprint without sacrificing capability.

“Arizonans understand how critical equipment costs are to running a business. 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,” said Congresswoman Debbie Lesko, who represents Arizona’s 8th Congressional District and serves on the U.S. House Committee on Energy and Commerce.

Negative carbon intensity RNG is created by trapping methane at its biogenic source, preventing it from escaping to the atmosphere, and turning it into transportation-grade renewable fuel, said Derick Turbide, Clean Energy vice president.

“The feedback in the development process is invaluable to the product's long-term success for our customers. The suite of integrated Cummins technologies used on these trucks from engine, aftertreatment, and fuel storage to transmission, axles, and the digital features that pull them all together in their most optimized form demonstrates the value of our next generation of product to our customers,” said José Samperio, vice president North American On-Highway Business, Cummins.