Originally Posted By: rationull
Just to be clear, are these mpg figures based on EPA ratings or some other ratings gathered specifically for CAFE? They seem too unrealistically high to be EPA ratings...
This is NHTSA's ambiguous answer:
"Do NHTSA’s CAFE values differ from EPA’s fuel economy data?
Three different sets of fuel economy values- NHTSA’s CAFE values, EPA’s unadjusted dynamometer values, and EPA’s adjusted on-road values exist. NHTSA’s CAFE values are used to determine manufacturers’ compliance with the applicable average fuel economy standards and to develop its annual report, the Automotive Fuel Economy Program Annual Update. The EPA’s unadjusted dynamometer values are calculated from the emissions generated during the testing using a carbon balance equation. EPA knows the amount of carbon in the fuel, so by measuring the carbon compounds expelled in the exhaust they can calculate the fuel economy. EPA’s adjusted on-road values are those values listed in the Fuel Economy Guide and on new vehicle labels, adjusted to account for the in-use shortfall of EPA dynamometer test values."
Just to be clear, are these mpg figures based on EPA ratings or some other ratings gathered specifically for CAFE? They seem too unrealistically high to be EPA ratings...
This is NHTSA's ambiguous answer:
"Do NHTSA’s CAFE values differ from EPA’s fuel economy data?
Three different sets of fuel economy values- NHTSA’s CAFE values, EPA’s unadjusted dynamometer values, and EPA’s adjusted on-road values exist. NHTSA’s CAFE values are used to determine manufacturers’ compliance with the applicable average fuel economy standards and to develop its annual report, the Automotive Fuel Economy Program Annual Update. The EPA’s unadjusted dynamometer values are calculated from the emissions generated during the testing using a carbon balance equation. EPA knows the amount of carbon in the fuel, so by measuring the carbon compounds expelled in the exhaust they can calculate the fuel economy. EPA’s adjusted on-road values are those values listed in the Fuel Economy Guide and on new vehicle labels, adjusted to account for the in-use shortfall of EPA dynamometer test values."