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Regulations for Emissions from Vehicles and Engines

E85 Flexible Fuel Vehicle Weighting Factor (F-factor) for Model Years 2021 and Later Vehicles

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Rule Summary

EPA is requesting comment on data sources and analytical approaches on which to base an EPA determination of an updated weighting factor (F-factor) for E85 flexible fuel vehicles for model years 2021 and later. The F-factor for a given vehicle model year is used to weight the greenhouse gas (GHG) emissions of a flexible fuel vehicle operating on E85 with the GHG emissions of the vehicle operating on conventional gasoline, when calculating the compliance value for that model year. The F-factor is also used in the Corporate Average Fuel Economy program for weighting the measured fuel economy of flexible fuel vehicles when operating on E85.

In a recent letter to auto manufacturers, EPA has extended to model year 2020 and later the previously established weighting factor (F-factor) for E85 flexible fuel vehicles (FFVs) of 0.14. While it is EPA’s intention to update the F-factor for MYs 2021 and later, in the event EPA is unable to resolve the uncertainties in a timely manner, this letter provides an F-factor of 0.14 for model years beyond 2020 as well. The 0.14 F-factor will be available for use in compliance calculations for MY 2020 and later, unless and until it is changed by EPA through a new determination. EPA will take public input into consideration as we update the F-factor analysis for future model years.

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