Tech Brief
CARB and EPA Low NOx Engines and Trucks Announced
Background
Both California (CARB) and the U.S. EPA have set stringent standards for limiting NOx emissions from heavy-duty trucks. We have covered these standards previously. Without going into the intricacies of the rules and the differences, it is important to point out that compared to today, California requires an intermediate 75% reduction of NOx starting model year (MY) 2024, while starting MY 2027, the final EPA tailpipe standards apply across the country and require a NOx reduction of 82.5% on existing FTP & RMC lab transient test cycles.
Low NOx Trucks Announced
In the last month or so, several truck manufacturers have announced the availability of new models that will comply with California’s MY 2024 requirements. These include, Kenworth, Peterbilt and Volvo Trucks North America. Cummins has also announced its redesigned X15 diesel which will meet EPA 2027 standards.
Image: Peterbilt
The table below gives a high-level overview of the engines and the advanced after-treatment systems deployed. Key trends include the use of an 48V electric heater (different locations) and dual SCR with twin dosing. Of course, the engines are also improved significantly considering that the EPA GHG standards also tighten in MY 2024 and MY 2027, but those changes are not covered here.
Sign up here to receive such summaries and a monthly newsletter highlighting the latest developments in transport decarbonization
Recent Posts
President Trump’s Day One Executive Order and Implications for Transport
President Trump’s Day One Executive Order and the Implications for Transport Emissions
Summary of IRA section 45W for Commercial Clean Vehicles
A summary of the 45W tax credit for the purchase of qualified clean commercial vehicles, published by the IRS.
Cummins launches the new MY 2025 6.7L engine for RAM trucks
Cummins and Stellantis have announced the launch of a new 2025 6.7L engine paired with the RAM lineup of pickup and chassis cab heavy-duty trucks.