On a recent special episode of Truck Tech, Alan Adler was joined by Shawn Hricko, Jamestown Engine Plant manager with Cummins, to discuss the nuts and bolts of the X15N natural gas engine (X15N).
The X15N begins with the X15 powertrain, which, Adler notes, is currently used by one in every three Class 8 trucks on the road. The second key component comes from Cummins’ decades-long experience developing and building the ISX12N natural gas engine. It was designed for regional haul and vocational trucks but lacked the torque and horsepower required for long-haul applications.
Compared with the smaller 12-liter engine, the 15-liter natural gas engine unlocks a new heavy-duty long-haul truck market, delivering diesel-like performance and significantly lower environmental impact.
“We’ve tested it out at Loveland Pass [Colorado] which is about 12,000 feet of elevation, pulling heavy loads,” said Hricko. “This has been tried and true; the X15N performs like a 15-liter diesel.” Cummins has performed about 1.5 million miles’ worth of testing on the engines in the U.S.
“The general architecture has been used in China for about 3.5 billion miles, so we got a lot of testing on the engine, but this is custom-built for the U.S. market,” Hricko said. “Some of these adjustments came in response to emissions regulations and standards in addition to customer-specific requirements.”
Today, major fleets in the U.S. are already testing the X15N engines in the field. Early feedback from customers praised its durability and diesel-like performance, a big upgrade from Cummins’ previous attempts at using the smaller ISX12N natural gas engine.
Every engine built with a customer in mind
Cummins’ order volumes and customer list are growing, and the company noted its existing production facility at Jamestown Engine in New York is up to the task. Hricko said currently truck OEM Paccar, Kenworth and Peterbilt brands are offering trucks with the X15N. He said additional OEMs will adopt the exact same engine in 2025.
More customers means more production. “Every engine that’s line-set here at the Jamestown Engine Plant already has an end customer in mind, and we built it for that end customer right now from the beginning of the block being set on the line to the final valve cover to the paint that’s put on at the end,” Hricko says.
He said 40 leading fleets have already placed orders for trucks equipped with the X15N. About 30% of those fleets have not used natural gas previously. The adoption of fleets traditionally tied to diesel engines is part of a trend, according to Adler: Some industry analysts are predicting up to 20% market penetration for natural gas engines in the Class 8 space.
In the event of runaway growth and demand, the Jamestown Engine facility is well equipped to handle it, boasting two lines – one operating at a more cost-efficient high volume, and a low-volume line that has added flexibility. Hricko said, “We’ve chosen to integrate this on our lower-volume assembly line at this current moment, which has flexibility up to 25% to 30% more than what we’re projecting that we need to build now.”
If demand outgrows that line’s capability, Hricko added, “then I can also build it on my secondary line, which is my high-efficiency line as well, so that opens up endless possibilities for how many of these engines that I can produce here at the plant.”
Hundreds of pounds lighter and 10% more fuel economy
Compared with the older-model ISX12N, the new X15N has around 10% more fuel economy and is a few hundred pounds lighter, taking advantage of improved structural changes and durability requirements. Every pound counts, and Hricko added that “if this engine weighs 200 pounds lighter than the current engine, then that’s 200 pounds more goods they can put in the back and haul.” Less tractor weight allows more potential payload weight.
For renewable natural gas (RNG), considered the cleanest form of natural gas in terms of emissions reduction, Hricko gave an example of a dairy customer that uses its herds of cows as the engine to create RNG, which then powers its fleet to deliver the dairy products. Adler added that RNG from dairy farms is one of the best sources, achieving emissions levels that are 300% below zero.
Adler also spoke with Puneet Jhawar, former general manager of alternative fuels at Cummins, at the Advanced Clean Transportation Expo in Anaheim, California, in May. Jhawar noted that compared to the U.S. market, there are over 40,000 X15N engines deployed worldwide with ratings of up to 500 horsepower and up to 1,850 lb-ft of torque.
Part of Cummins’ strategy when faced with multiple competing fuel sources was to put them under one high-efficiency, low-emissions (HELM) platform, based on the X15 engine block with a custom fuel header. An added benefit for RNG, he says, is that more RNG plants are coming online to help support/meet demand. “There’s a lot of new RNG plants that are coming up; I think about 200, 250 are already in production. There’s another 100 or so coming online.”
Whether diesel and its distillate go the way of the dinosaur that created it remains to be seen. “I think it’s going to depend on a lot of factors,” Jhawar said. He predicts that until the end of the decade, diesel is going to remain as it has a long tail, but natural gas will gain ground with trucking industry adoption and as more infrastructure comes online.To learn more about Hexagon Agility, visit hexagonagility.com or follow on LinkedIn.
