2025 was a year of uncertainty and disruption, and one question was whether the Environmental Protection Agency would proceed with or delay the 2027 heavy-duty truck emissions regulations.

Late in the year, we heard from the American Trucking Associations that the 2027 nitrogen-oxide (NOx) emissions limits will partially go into effect in 2027. There’s been no official announcement from EPA, but the general expectation is that the agency will announce changes to the rule by mid-2026.

“We are encouraged by several proposed adjustments that should help lower costs and ease implementation,” ATA Vice President of Energy and Environmental Affairs Patrick Kelly said in a message to federation membership obtained by Transport Topics. TT reported that according to that message, EPA had informed ATA it “does not plan to meet” the federation’s request for a four-year delay of the rules.

So, that’s more clarity than we had before on 2027 emissions, but there’s still a lot we don’t know.

"EPA’s intention to keep the 2027 start date — even as it works on revisions — leaves carriers preparing for a rule whose final requirements are not yet fully known,” the Pennsylvania Motor Truck Association said in a message to members.

So what will change in the rules?

How Will 2027 EPA Engine Rules Change?

Industry insiders say the most likely change is that the increased useful life and warranty provisions will be removed from the rule or postponed. These provisions were anticipated to be the biggest factor in driving up the cost of new trucks meeting the 2027 rules.

Ken Vieth, president of ACT Research, estimated that two-thirds of the previously anticipated higher price for 2027 engines was going to be extending the warranty provisions. 

Without that, he said, “instead of a $25,000 mandate, it's probably more like an $8,000 mandate.”

The news, although unofficial, will likely give fleets new motivation to prebuy in 2026.

A large prebuy isn’t likely, however. As Tim Denoyer, vice president and senior analyst at ACT Research, explained, “fleets are still managing down excess capacity from overbuying in 2023-2024, and investment dollars are scarce amid generationally low for-hire truckload profit margins.

“But Class 8 orders tend to move with spot rates, regardless of the sustainability of the trend, and this dynamic provides a degree of moderation for the 2026 rate outlook,” he added.

More Reasons Fleets May Pre-Buy Trucks Ahead of 2027 Model Year

Brian Antonellis, senior vice president of fleet operations for Fleet Advantage, told HDT last summer that he expected truck makers to move ahead with the EPA 2027-compliant diesel technology. 

Like Vieth, he estimated that would mean a price increase of $8,000 to $10,000 per truck.

If freight demand shows some recovery this year, Antonellis said, the added cost alone could encourage a limited prebuy ahead of the 2027 model year.

He also pointed to early indications that fuel efficiency on 2027-model trucks could slip slightly compared with current offerings. One reason is the potential shift by more OEMs to 24-volt electrical systems, which allow aftertreatment to run hotter to meet the new standards.

Taken together, higher vehicle prices and the risk of lower fuel efficiency could push some fleets to accelerate purchasing decisions in 2026, he said. Not a big prebuy, but what he called “a strategic prebuy in Q3 and Q4 of 2026, similar to what we saw back in 2012.”

What Trucking Fleets Have Been Doing About a 2027 Prebuy

Some trucking fleets told Heavy Duty Trucking that they have already been doing something of a pre-buy.

Brent Hickman, senior manager of equipment, maintenance and fleet sales at Pilot Company, said while there had been some hope in the industry of the 2027 EPA regulations disappearing altogether, “It's a little harder than just a swipe of a pen to make all those regulations go away.

“The OEMs have already put all the technology, put the research, put everything in place,” said the 2023 HDT Truck Fleet Innovator in a recent interview. “The 2027 emission standards are going to happen.”

With or without the longer warranty and useful life requirements, he said, there was little question the trucks would be more expensive. So Pilot decided to be a little more aggressive on its 2026 truck orders.

“Not exactly a pre-buy, but purchasing a little bit heavier so that we can be lighter in 2027,” Hickman said. “Simply to avoid any technology or any new challenges that come with what the OEMs are putting out there to meet those standards.” 

‘Somebody Else Can Work Through the Bugs’

Kyle Neumann, vice president at the Foodliner private fleet, said they wanted to stay away from the 2027s as much as they could. 

“So we started three years ago doing a little bit of a pre-buy, so to speak, and pulling the trucks that we would be normally trading on calendar year 2027 forward," explained the 2024 HDT Truck Fleet Innovator.

“So right now, the 2027 calendar year is going to be a pretty slow year for us for buying trucks. Somebody else can work through the bugs” that always happen with new emissions technology.

Bruce Stockton, who consults with trucking fleets on equipment, maintenance, and safety issues under the name Stockton Solutions, said he recently spoke with a fleet in the process of buying 100 trucks.

All three of the truck makers this carrier got quotes from, he said, offered to hold the price if they ordered trucks now for delivery in 2026, regardless of what happened with tariffs.