There looks to be a shift away from spec’ing 14L engines in new Class 8 trucks in favor of powerplants that range from over 10L to under 14L in displacement. And the trend to smaller-displacement engine is expected to continue as diesel’s market hegemony comes “under attack” by alternative power.
Class 8 Engines: Is Smaller Displacement the Wave of the Future?
There looks to be a shift away from spec'ing 14L engines in new Class 8 trucks in favor of powerplants that range from over 10L to under 14L in displacement, according to ACT Research and Rhein Associates.

An example of a less than 14L and over 10L engine is the 12.8L Detroit DD13.
Photo: Detroit Diesel Corp.
That analysis is included in the N.A. Commercial Vehicle On-Highway Engine Outlookreport recentlypublished by ACT Research and Rhein Associates, which predicts that engines over 10L will account for more than 85% of the Class 8 production between 2020 and 2024.
“Although the over-14L engine category will remain the largest segment in 2019, there is a trend to smaller-displacement engines in the over 10L market segment for Class 8 trucks and tractors, with an acceleration prompted by new emission regulations expected in 2024,” said Tom Rhein, president of Rhein Associates.
For Class 5-7, he said, "the current metric of interest is gasoline penetration, which continues to see share gains.”
Kenny Vieth, ACT president and senior analyst, noted that, “Diesel power is under attack long-term for use in on-highway commercial vehicles. Alternative power is being developed, tested, and refined, even as diesel engines are transitioning to become more fuel-efficient and clean.
“Emission regulations are one of the main drivers of alternative fuel adoption, which is why the Engine Outlook includes a section on the commercial vehicle regulatory environment,” he continued.
Vieth also offered a caution. “While many think this is a California-only phenomenon, we would note that Oregon’s legislators recently voted in favor of a bill to regulate diesel trucks in the Portland metro area, and we continue to see reports about various state and federal-level funding for alternative fuel programs that are sending millions of dollars toward these efforts for both commercial and passenger vehicle use.”
The engine report highlights power-source activity for Class 5 to 8 trucks and includes five-year forecasts of engines volumes and product trends. Rhein Associates is a supplier of powertrain information to worldwide clients. ACT Research is a publisher of commercial vehicle truck, trailer, and bus industry data, market analysis and forecasts for the North America and China markets.
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