An official website of the United States government.

This is not the current EPA website. To navigate to the current EPA website, please go to This website is historical material reflecting the EPA website as it existed on January 19, 2021. This website is no longer updated and links to external websites and some internal pages may not work. More information »

Regulations for Emissions from Vehicles and Engines

Direct Final Rule: Nonroad Diesel Technical Amendments and Tier 3 Technical Relief Provision

On this page:

Rule Summary

In this rulemaking, EPA is making certain technical corrections to the rules establishing emission standards for nonroad diesel engines. In addition, we are amending those rules to provide nonroad diesel equipment manufacturers with a production technical relief provision for Tier 3 equipment which is similar to the technical relief provision already available for Tier 4 equipment.

Additional Resources

Fact Sheet

Regulations for Emissions from Vehicles and Engines Home