Cummins Begins Field Testing X15N CNG Engine as Carbon Intensity of California RNG Supply Drops Further Below Zero

By California Natural Gas Vehicle Partnership

ANAHEIM, Calif., May 3, 2023 – At this year’s Advanced Clean Transportation (ACT) Expo, the California Natural Gas Vehicle Partnership (CNGVP) collaborated with Cummins Inc. to host a May 3rd media event showcasing the Cummins X15N 15-liter natural gas engine in a Class 8 truck chassis for the first time in North America. During the media event, Cummins shared insight into its plans to bring the X15N engine to market, including announcing that the company had begun field testing the engine with key fleet partners.

Cummins anticipates that starting in 2024, fleets will have the opportunity to order factory-built Class 8 trucks with the Cummins X15N 15-liter engine as PACCAR has announced availability in both the Kenworth and Peterbilt brands. Designed as an economic and environmental sustainability solution for heavy-duty transport, the Cummins X15N engine will enable fleets to achieve powerful performance with a range of at least 750 miles even when hauling 82,000-pound loads over challenging terrains.

“With mounting environmental regulations and a focus on making progress towards corporate sustainability goals, fleet owners are making critical decisions about the future makeup of their fleet,” said Tom Swenson, manager-global regulatory affairs, Cummins Inc. and CNGVP president. “Class 8 trucks featuring the X15N engine are an attractive fleet sustainability option, as they offer fleets the closest direct replacement for diesel trucks in terms of operational performance. With the growing supply of carbon-negative renewable natural gas (RNG) in California and the reintroduction of the Alternative Fuel Tax Credit, fleets have an incredible opportunity to reduce both their environmental impact and overall operating costs.”

During CNGVP’s 2023 ACT Expo press conference, Cummins shared that it would be delivering 25 Class 8 trucks upfit with the X15N engine for fleet field tests. Through September 2023, the X15N engine technology will be demonstrated across a variety of applications, terrains and locations throughout the United States, providing Cummins with valuable real-world operating data that will be used to validate its commercial production plans. California fleets taking part in the field tests include National Ready Mixed Concrete Company, Walmart, Matheson, Food Express, and Sandman.

“Our team is excited to be a part of the Cummins X15N field trials and to have the opportunity to test these natural gas engines in our cement and aggregate hauler fleet,” said Steve Lode, president, National Ready Mixed Concrete. “When looking across a variety of factors including range, fueling frequency and speed, hauling capacity, and maintenance support, we believe that trucks with the X15N engine will hold up to diesel trucks better than any other commercially available low-emission vehicle technology. Additionally, the utilization of RNG provides the ONLY available fuel source technology to achieve massive reductions in our GHG emissions, an extremely critical objective of our company. RNG also offers us the best opportunity to keep our costs down when compared to diesel and other alternative fuels.”

RNG consumed by vehicles in California – which is produced from a variety of organic and renewable sources, including wastewater treatment plants, food and green waste, landfills, dairies, and more – had an energy weighted average carbon intensity of -87.74 gCO2e/MJ for calendar year 2022, according to California’s Low Carbon Fuel Standard (LCFS) program data reported on April 28, 2023. Growth in the volume of swine and dairy gas being reported into California’s LCFS program is the main factor continuing to drive the carbon intensity of the state’s natural gas transportation fuel to plunge further and further below zero carbon. During 2022, RNG made up approximately 98% of all natural gas used for transportation fuel in California for the second year in a row.

Beyond reducing emissions, fleet operators can save money on fuel costs by using natural gas, which supported a clear cost advantage over diesel throughout 2022. On average, the pump price for natural gas in 2022 was $2.73 per diesel gallon equivalent (DGE), while diesel fuel averaged well over $5/gallon according to the United States Department of Energy. Fleets with onsite natural gas fueling infrastructure and well-negotiated fueling contracts report RNG prices as low as $1.00 per DGE. Several federal tax credits are available to help fleets benefit from utilizing natural gas fuel, including the recently reauthorized Alternative Fuel Tax Credit of $0.50 per gallon passed as part of the Inflation Reduction Act (IRA) in 2022. Under the IRA, a Clean Fuel Production Credit of ~ $1.00 per gallon was also created to reduce the cost of producing natural gas for fleets.

To learn about the near-zero emissions Cummins X15N engine and follow the customer journeys of those involved with the field test, visit