The U.S. Environmental Protection Agency (EPA) on Tuesday updated emission standards for heavy-duty commercial vehicles for the 2027 model year, tightening tailpipe NOx limits to a level 80%-plus below the current standard and reducing the particulate matter limit by 50%. The agency also will require that OEMs extend warranties to 450,000 miles from 100,000 and useful life limits to 650,000 miles from 435,000 miles.
The new standards require heavy-duty commercial vehicles to limit nitrogen oxide (NOx) emissions to 0.035 grams per horsepower-hour during normal operation, 0.050 grams at low load, and 10.0 grams at idle, and will also increase the useful life of governed vehicles by 1.5 to 2.5 times and yield emissions warranties that are 2.8 to 4.5 times longer – provisions that guarantee that as vehicles age, they will continue to meet EPA’s more stringent emissions standards for a longer period of time.
The 1,153-page rule also requires manufacturers to better ensure that vehicle engines and emission control systems work properly on the road, including demonstrating that engines are designed to prevent drivers and fleets from tampering with emission controls by limiting tamper-prone access to electronic pollution controls.
EPA estimates that direct incremental manufacturing costs to meet the new regs – including the technology costs, plus some costs to improve the durability of the technology through regulatory useful life – to be just more than $2,300 for a heavy-duty diesel engine.
Jed Mandel, president of the Truck and Engine Manufacturers Association (EMA), whose membership includes Cummins, Navistar, Volvo Group, Daimler Truck North America (DTNA) and Paccar among others, said the rule – which he called “very stringent” – will be difficult to implement.
"While we believe zero-emission vehicles are the future of our industry, we’re also committed to delivering lower NOx from our diesel products." John Mies, Volvo Group Senior Vice President of Corporate Communications
