Briefing Snapshot

  • Paccar will begin updating truck software for vehicles equipped with MX-11 and MX-13 engines, following revised diesel exhaust fluid (DEF) inducement guidance from the U.S. Environmental Protection Agency (EPA), according to a July 6 press release.
  • Trucks built after July 20 will come with the new software pre-installed, while trucks built after 2018 can be updated at Kenworth and Peterbilt dealerships.
  • The software aims to improve reliability and reduce operational disruptions by raising the final inducement speed limit and giving drivers more time to address emissions-related issues before the speed limit takes effect.

In-Depth Analysis

Paccar is the second major manufacturer to roll out a software upgrade since the EPA updated its guidance in March. The EPA's revisions allow manufacturers to use alternative monitoring technologies, including software-based methods, and state that the changes aim to improve system reliability while maintaining emissions compliance.

Under the updated guidance, Paccar's software raises the final inducement speed limit from 5 miles per hour to 25 miles per hour. The time drivers have to address parts or DEF quality issues also extends from 5 hours to 160 hours before reaching the final inducement speed limit.

Daimler Truck North America announced in June plans to update approximately 330,000 in-use trucks. Newly produced Freightliner and Western Star vehicles already come with the updated software pre-installed.

Although the EPA's recent guidance was expected to provide relief for trucking and agricultural businesses—which had reported DEF sensor equipment failures—the agency last week also proposed a rule to revise parts of its 2023 heavy-duty diesel engine nitrogen oxide regulations, including eliminating DEF-related engine derating and speed limits on new trucks.

Nevertheless, industry groups, including the American Trucking Associations (ATA), welcomed any regulatory relief earlier this year.

"The EPA's decision to allow manufacturers the flexibility to suspend these inducements and completely eliminate problematic sensors by monitoring actual truck emissions is a pragmatic solution that reflects how these systems perform in the real world," said Patrick Kelly, ATA's vice president of environmental affairs, in a March statement.