Action
Proposed rule.
Summary
The National Highway Traffic Safety Administration (NHTSA) is proposing minor technical amendments to the test procedures for heavy- duty engines and vehicles to improve accuracy and reduce testing burden. These amendments affect the certification procedures for fuel efficiency standards and related requirements. These proposed amendments increase compliance flexibility, harmonize with other requirements, add clarity, correct errors, and streamline the regulations. Given the nature of the proposed changes, NHTSA does not expect either significant environmental impacts or significant economic impacts for any sector.