International Lines Up EPA 2027 S13 Powertrain
OEM Updates Powertrain Ahead of Regulatory Transition
Key Takeaways:
- International Motors detailed plans for its S13 integrated powertrain to meet EPA’s 2027 heavy-duty truck emissions rules and said it is proceeding as if the standards take effect Jan. 1, 2027.
- The rules require NOx emissions to fall to 35 mg per horsepower-hour from 200, creating cost and timing uncertainty as EPA considers technical adjustments despite rejecting a delay request.
- International expects S13 availability around mid-2026 and dealer training in late 2026, though weak freight markets and unclear regulations cloud demand and pricing.
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International Motors detailed plans for its upcoming S13 integrated powertrain designed to comply with Environmental Protection Agency emissions requirements for 2027 model-year trucks, a deadline it and other manufacturers must hit despite some uncertainty surrounding details on the final rule.
“We are marching forward as though this emissions regulation lands at the beginning of 2027,” Dan Kayser, executive vice president of commercial operations at International, said during a Jan. 7 media roundtable. “We haven’t altered our plans there at all. We’re marching [on] as though this happens January of 2027. We have no reason to believe that won’t be the case.”
American Trucking Associations in August 2025 asked EPA to delay by four years implementation of the rules’ stricter nitrogen oxide limits, citing “substantial compliance costs and operational burdens at a time when the trucking industry is already contending with historically difficult market conditions.” The federation in November notified members that EPA had rejected that request, but said the agency through an ongoing rulemaking may make other adjustments. Among them are the possible elimination of extended warranty periods set to take effect in 2027, along with revisions to “useful life standards” and other technical changes.
Lingering uncertainty over the rule’s future driven by EPA statements from March 2025 about stalling certain pending regulations compelled Cummins in August to delay the launch of its 2027-compliant X15 diesel engine.
EPA told ATA it will leave in place a Biden-era requirement that NOx emissions for heavy-duty trucks drop to 35 milligrams per horsepower-hour from 200 mg/horsepower-hour. The agency is expected to publish an in March or April.
Availability for the updated S13 powertrain is likely a few months away, Kayser said.
“My best estimate is probably mid-2026 as a rough estimate, but it’s just a rough estimate at this point in time as to what I would expect,” he told Transport Topics. A full understanding of the regulations is needed before the order book opens, and the same is true for pricing, he noted.
“There are costs associated with the new emission standard that aren’t just the products — they’re useful life, warranty, and so forth and so on,” Kayser said. “We don’t have great clarity yet on those pieces, which makes it a little bit hard to really lean in.”
Analysts and OEMs had expected a robust so-called “pre-buy” of 2025 and 2026 model-year trucks from fleets in the lead-up to the 2027 rules, but a persistently weak freight market has kept customers on the sidelines.
Powertrain Enhancements
The S13 integrated powertrain was initially launched in August 2022.
Enhancements for the updated powertrain include:
- Variable valve timing for the S13 engine, enabling variable valve braking for improved braking performance.
- A 24-volt transmission control module for the T14 transmission with predictive shifting using GPS/topography data.
- A standardized 24-volt electrical architecture across the powertrain platform, which can enhance cold-crank performance. A 12-volt cab and chassis electrical system is retained.
“[Exhaust gas recirculation] is fully eliminated,” said International VP of Integrated Sales David Hillman. “The compression release brake performance is going to be noticeably better because of the variable valve technology that we’re bringing to the market. The transmission gets the benefit of even faster and smoother shifts with the electronic clutch actuator because we’re running on 24 volts.”
Kayser noted that service training at dealers will begin in late 2026. “We’ve been preparing for EPA 2027 for years. Our customers won’t face surprises, only the same proven powertrain,” he said in a statement.
Kayser noted that the engine upgrades are part of wider changes at International. The company unveiled a revamp of its HV series of vocational Class 8 trucks in September 2024.
Kayser stressed that the market outlook for trucks with the new powertrain remains murky.
“The market’s still very weak, and we expect ’26 to at least start out in a fairly weak position, and then we’ll see where it goes,” he said. “It’s very hard right now to predict what order intake will be. It’s been quite hard throughout 2025.”
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He noted, however, that December showed some hopeful signs.
“December was certainly, from a historic perspective, strong,” Kayser said. “We think that a little bit of further clarification on sort of tariff impacts and [possibly] allowed people to think a little bit more openly about releasing [capital expenditures] now. The big question is: Is this a blip on the radar screen? In January, I’m going to be looking with a very close set of eyes to see if we see any carryover.”
December’s preliminary North America Class 8 net orders totaled 42,700 units, a jump of 16% year over year, according to ACT Research data released Jan. 5.
In contrast, November orders slumped 47% year on year to 19,700, ACT said. The 10-year average for the month is 28,910, according to FTR Transportation Intelligence. Truck makers’ order books for the coming calendar year typically open in September.
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