On the Dash:
- EPA’s proposal keeps warranty periods at 100,000 miles instead of extending them to 450,000
- Useful life extension delayed three years, taking effect in model year 2030 instead of 2027
- EDF opposes the rollback, citing pollution risks to 72 million people near freight routes
The Environmental Protection Agency (EPA) proposed changes to emission standards for heavy-duty trucks and engines built starting in model year 2027. The agency estimates the changes will save the trucking industry $12 billion, including up to $6,000 per new truck.
The proposal targets a 2023 rule that extended emission-related warranties from 100,000 miles or five years to 450,000 miles or 10 years for the heaviest engines. It also extended the useful life period, when engines must keep meeting emissions limits, from 435,000 miles to 650,000 miles.
Emissions & safeguards that stay in place
Under the new proposal, warranties would stay at 100,000 miles or five years for model year 2027 and later engines. The extended useful life requirement would still take effect, but three years later than planned, in model year 2030 instead of 2027.
The EPA also proposed eliminating mandatory power and speed reductions triggered by diesel exhaust fluid system failures. Trucks would instead alert drivers to the problem while continuing to operate normally. The change would apply to on-highway trucks, off-road engines and farm machinery.
The proposal keeps the underlying NOx (nitrogen oxides) emissions limits from the 2023 rule in place. The agency projects the changes will still preserve nearly 90% of the NOx reductions originally expected under that rule. It also keeps a 5% production allowance for engines that don’t meet 2027 standards, without requiring manufacturers to use emissions credits to access it. The EPA said this provision helps manufacturers of specialized vehicles such as fire trucks, garbage trucks, and concrete mixers.
Opposition from environmental groups
Conversely, the proposed changes face opposition from environmental groups including the Environmental Defense Fund (EDF). The EDF argues that it would reduce protections against harmful pollution from buses and trucks. Although these heavy-duty vehicles account for only 5% of all vehicles, they generate the highest levels of smog-causing NOx pollution among transportation sources. The defense agency cites EPA’s own estimate that 72 million people live within 200 meters of a truck freight route, often in low-income communities.
However, the EDF also questions the EPA’s reasoning. Major manufacturers, including Daimler, Cummins, Volvo and PACCAR, have already built engines that meet the 2027 standards, the group says. That undercuts EPA’s claim that manufacturers need more time to solve technical problems.
Written comments on the proposal are due by August 29. The EPA also plans to hold a virtual public hearing.
