NHTSA proposes rule on heavy-duty engine/vehicle test procedures

September 12, 2022

Tyson Fisher


The National Highway Traffic Safety Administration is proposing amendments to test procedures for heavy-duty engines and vehicles, but the rule no longer includes trailers.

NHTSA’s proposed rule includes “minor technical amendments” to the test procedures “to improve accuracy and reduce test burden.”

These amendments affect the certification procedures for fuel efficiency standards. They also increase compliance flexibility, harmonize with other requirements, add clarity, correct errors, and streamline the regulations, according to NHTSA.

NHTSA does not expect either significant environmental impacts or significant economic impacts for any sector.

The proposed rule affects companies that manufacture, sell, or import into the United States new heavy-duty engines and new Class 2b through 8 trucks, including combination tractors, vocational vehicles including municipal, commercial, recreational vehicles, and 3⁄4-ton and 1-ton pickup trucks and vans.

The proposed rule amends the regulations that implement NHTSA’s fuel efficiency standards for engines and vehicles. The proposed amendments are technical in nature and include corrections and clarifications to a variety of existing regulatory provisions to improve consistency with related Environmental Protection Agency standards and with NHTSA’s original intent for those provisions, according to the proposed rule.

The proposal comprises a variety of small changes for multiple types of engines and vehicles. However, trailers have been omitted from the standards after a federal court ruled that trailers are not considered vehicles. Essentially, trailers are not considered vehicles in this context as they are “motorless and use no fuel.”

For more information on that court case, click here.

NHTSA will be accepting comments on the proposed rule for 60 days beginning Sept. 13. To submit comments, click here. LL