02/19/2026
EPA Wants DEF Data
Regulations, Business, Commercial Trucking, President Biden, President Donald J. Trump
The Environmental Protection Agency (EPA) has taken a step back in terms of its raw enforcement ever since the transition to the second Trump Administration from President Joe Biden, but that does not mean the EPA is doing absolutely nothing to manage the environment. In an attempt to balance economic growth with environmental health, the EPA is demanding that original equipment manufacturers submit data on their Diesel Exhaust Fluid (DEF) system failures.
Details
DEF reduces the amount of nitrogen oxides (NOx) that are released as a truck or other vehicle travels. If the system malfunctions, the vehicle is still able to operate as normal, but the amount of particulates it releases into the air increases dramatically while also decreasing the amount of power the drivetrain is allowed to use to mitigate the damage. EPA Administrator Lee Zeldin wants to prevent these malfunctions, calling the directive “common sense.”
“EPA understands this is a massive issue, which is why we have already established commonsense guidance for manufacturers to update DEF systems,” EPA Administrator Zeldin stated on Feb. 3. “Today, we are furthering that work and demanding detailed data to hold manufacturers accountable for the continued system failures. The Trump EPA is committed to ending unnecessary frustrations and days lost on the road and in the field for American farmers and truckers.”
The EPA hopes that by collecting this data, it can provide the best possible guidance on what to do to make sure that DEF systems continue to run for as long as possible before needing repair.
Conclusion
Additionally, the EPA wants to change how derating, the act of reducing power to the drivetrain, works upon a DEF system failure:
The first ten hours would have no change.
For two weeks after the first ten hours, torque would be reduced by 15%.
After that, the truck would be hard-capped to 25 miles per hour, just enough speed to get to the shop.
The EPA believes that this is a good compromise between environmental and economic regulations, allowing a truck to complete its delivery and also make it to a repair shop safely while also reduce the impact those who ignore the system warnings have on the environment.
