As the trucking industry looks toward the 2027 Environmental Protection Agency (EPA) emissions standards, a panel of powertrain experts at ACT Expo 2026 in Las Vegas Monday emphasized that diesel remains the dominant and most viable solution for the near future.
The discussion featured leaders from Volvo Group, International Motors, Cummins, and Daimler Truck North America (DTNA) with an overarching theme was a commitment to meeting strict NOx reduction requirements without sacrificing the total cost of ownership (TCO) or vehicle uptime.
Efficiency and compliance
Mehdi Ferhan, head of powertrain technology for Volvo Group; Navtej Singh, director of engineering at International Motors; Lyle Kocher, Cummins' director technical programs and planning; DTNA Director of Field Sales Engineering Steve Collins.
Mehdi Ferhan, head of powertrain technology for Volvo Group, described the upcoming regulations as a "battle to win," noting that Volvo is building on its legacy architecture to ensure reliability while hitting an 80% reduction in engine-out NOx.
Lyle Kocher, Cummins' director technical programs and planning, highlighted the role of "smarter controls" and targeted thermal management. By using heaters within the aftertreatment system, Cummins aims to maintain optimal temperatures for NOx conversion, particularly during low-load duty cycles, without taxing the engine's fuel efficiency.
Simplification and reliability
A major concern for fleet operators is the increasing complexity of engine systems. Navtej Singh, director of engineering at International Motors, said his company's strategy involves simplifying the engine to focus solely on power and torque, leaving the chemical cleaning process to the aftertreatment system.
"We are making it so simplified," Singh said, referring to International’s S13 powertrain. "We are looking at the customer’s pain point... it is very much what the customer wants."
[Related: Trucking industry braces for EPA 2027 regs amid cost and warranty concerns]
DTNA Director of Field Sales Engineering Steve Collins agreed, adding that Detroit has actually moved toward a simpler fuel system for its Gen 6 engine. By leveraging a more robust aftertreatment design, engineers were able to eliminate complicated amplified injectors in favor of a simpler high-pressure fuel pump and common rail setup.
The role of diesel in a decarbonized future
While alternative fuels like electric, hydrogen, and natural gas continue to grow, the panelists agreed that diesel's infrastructure, power density, and proven reliability keep it at the forefront.
"Diesel just continues to dominate because of the flexibility and the power that it delivers," Kocher said. Collins added that the advancements in aftertreatment technology have actually pushed the bar higher for alternative solutions to compete on a TCO basis.
Looking toward the next decade, the panel suggested that technologies like hybrid powertrains could serve as an important bridge. Volvo and International also noted that their engine platforms are increasingly "multi-energy," designed for diesel but adaptable for gas, electric, or hydrogen as market demands and infrastructure evolve.
Digital transformation: Uptime and diagnostics
To combat the challenges of more advanced technology, the manufacturers are leaning heavily into connectivity and prognostics. Fleet managers can expect more precise over the air updates and service alerts that allow dealers to identify potential failures before they occur.
"The complexity, while it's real, it's managed by the system and hopefully not by the fleets," Kocher said. "That's the partnership we're looking for."
The workshop concluded with a consensus that the clean diesel era is far from over, with the industry prepared to deliver more efficient, durable, and environmentally compliant engines to the North American market by 2027.
