Cummins' 15-liter gives nat gas the hype it's lacked for decades

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Clean Energy Peterbilt
Clean Energy, the largest provider of the cleanest fuel for the transportation market, debuted its demo truck this week at ACT Expo, equipped with the X15N natural gas engine.

It's hard to consider ACT Expo, an alternative fuel and green energy transportation trade show held this week in Las Vegas, anything other than a battery-electric truck showcase, but alternative solutions were absolutely on hand – specifically, natural gas. 

Cummins' 15-liter natural gas engine, announced in 2021, has sparked excitement in the space like never before; namely because it fills a gap in big power that for many years seemed unlikely. The Cummins X15N is the industry’s first 15-liter natural gas engine that delivers diesel-like power, range, and performance, making it appealing for short, regional, and long-haul operations.

Powered by Compressed Natural Gas (CNG), Renewable Natural Gas (RNG) or Liquified Natural Gas (LNG), the X15N produces between 400 and 500 hp with up to 1,850 lb.-ft. of torque and is compatible with Eaton Cummins Endurant and Allison transmissions. It also meets strict EPA emission requirements and CARB 2024 Low NOx standards and features up to a 10% improvement in fuel economy over Cummins’ 12-liter natural gas engine with similar rating and duty cycle.

[Related: Natural gas making its strongest-ever case for long haul]

Peterbilt CNG truckPeterbilt is making the Cummins X15N natural gas engine available on three models – 579, 567 and 520 – with orders also scheduled for production in the third quarter.Clean Energy, the largest provider of the clean fuels for the transportation market, debuted its demo truck this week at ACT Expo, equipped with the X15N natural gas engine. The truck will fuel with negative carbon-intensity, ultra clean renewable natural gas (RNG) – a transportation fuel made from organic waste, which drastically reduces carbon emissions by an average of 300% versus diesel.

Kenworth announced plans to kick off production of T680 and T880 models spec'd with the X15N natural gas engine in the third quarter this year. Peterbilt is making the Cummins X15N natural gas engine available on three models – 579, 567 and 520 – with orders also scheduled for production in the third quarter. 

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Customers can select factory frame drilling options for back of cab Cummins Clean Fuel Technologies or Hexagon Agility CNG/RNG fuel systems. Additional non-factory fuel systems are available to ensure flexibility for any application or configuration of the natural gas fuel system, including rail-mounted and body-mounted fuel storage. Back of cab natural gas fuel delivery systems can deliver up to a 175 diesel gallon equivalent (DGE). 

'Star' studded power

Cummins has found some high-profile Beta partners for its X15N, Walmart and Werner among them. But spec'd in an everyday Kenworth or Peterbilt, the X15N might go unnoticed to the untrained eye. However, it was also the engine of choice for Shell's CNG-powered Starship 3.0 concept tractor, which will soon set off on a nationwide tour following its four-day stop in Vegas. Starship 3.0 is equipped with 120 diesel gallon equivalent of natural gas, enough for roughly 600 miles between refuels. 

Just before heading to Vegas, Shell Starship 3.0 hit the road through North Carolina. During the run, performance data was collected to show its CO2 reduction and freight ton efficiency (FTE) capabilities. Those results were third-party monitored and will be verified by the North American Council for Freight Efficiency (NACFE), as has been done with all previous Starship demonstration runs.

Powered by a 2020 Cummins X15 400 EX Efficiency Series diesel engine paired up with a 12-speed Eaton Endurant transmission, the second generation Starship saw a nearly 21% gain in fuel economy at 10.8 mpg compared to Starship 1.0’s 8.94 mpg. Those figures compare to a national average of roughly 6.5 mpg for common on-highway tractors. 

Shell StarshipCummins' X15N was also the engine of choice for Shell's CNG-powered Starship 3.0 concept tractor, which will soon set off on a nationwide tour following its four-day stop in Vegas.

Jason Cannon has written about trucking and transportation for more than a decade and serves as Chief Editor of Commercial Carrier Journal. A Class A CDL holder, Jason is a graduate of the Porsche Sport Driving School, an honorary Duckmaster at The Peabody in Memphis, Tennessee, and a purple belt in Brazilian jiu jitsu. Reach him at [email protected].