The National Highway Traffic Safety Administration (NHTSA) and the Environmental Protection Agency (EPA) have made corrections in the proposed rules published in the Federal Register of November to establish a comprehensive national program that will increase fuel efficiency and reduce greenhouse gas (GHG) emissions for on-road heavy-duty vehicles.
That document inadvertently contained some incorrect fuel consumption values in NHTSA-specific tables in the preamble that resulted from using an incorrect conversion factor for determining CO2 emissions to equivalent fuel consumption for gasoline fuel. The correct values that should have been used in the document are a factor of 1,018 grams of CO2 per gallon of diesel for conversion of diesel fuel, and a factor of 8,887 grams of CO2 per gallon of gasoline for gasoline. That document also contained some rounding errors in NHTSA-specific tables in the preamble.
The new document corrects the rounding errors by adopting a uniform rounding approach for all fuel consumption equivalents for those NHTSA-specific tables and makes the appropriate corrections to the conversions.
The proposed regulatory text for both NHTSA and EPA is not affected.