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Regulations for Emissions from Vehicles and Engines

Vehicle Test Procedure Adjustments for Tier 3 Certification Test Fuel

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Rule Summary

EPA is proposing technical changes to emissions testing protocols and compliance calculations for the Light-duty Greenhouse Gas (GHG) Emissions Standards and Fuel Economy Standards that would provide a smooth transition from using test fuel with zero percent ethanol (E0) to test fuel that contains ten percent ethanol (E10). EPA is switching test fuels since the vast majority of gasoline supplied to consumers in the U.S. is now E10, and EPA’s Tier 3 criteria pollutant emissions standards for light-duty vehicles already use E10 as the test fuel. The purpose of this proposed rule is to ensure that the transition to E10 as a test fuel has no impact on the stringency of the Light-duty GHG Emissions and Fuel Economy Standards. The proposed transition to E10 as a test fuel will allow manufacturers to perform all of their vehicle testing on a single (E10) fuel for compliance with both Tier 3 and GHG Emission and Fuel Economy Standards.

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