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Regulations for Emissions from Vehicles and Engines

Direct Final Rule for Revisions to In-Use Testing for Heavy-Duty Diesel Engines and Vehicles; Emissions Measurement and Instrumentation; Not-to-Exceed Emission Standards; and Technical Amendments for Off-Highway Engines

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Rule Summary

The U.S. Environmental Protection Agency (EPA) is publishing a Direct Final Rulemaking to make several amendments to EPA’s mobile source emission standards and test procedures. These revisions affect the in-use particulate matter (PM) testing program for heavy-duty diesel engines, locomotives, spark-ignition (SI) marine engines, small SI engines, Tier 4 nonroad diesel engines, and PM measurement and assessment for both laboratory and field testing.

Additional Resources

Fact Sheet


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