Cars and Drivers

Average US Auto Fuel Economy Rating Ticks Down in December

Paul Ausick

Published: January 11, 2017 10:10 am

Last Updated: January 12, 2020 3:58 pm

The average fuel-economy rating for new vehicles sold in the United States in December 2016 was 24.9 miles per gallon, down 0.1 mpg compared with the revised November average. For all of 2016 the average fuel-economy rating for new vehicles sold was 25.2 mpg, down 0.1 mpg from the 2015 average.

For model year 2017, the EPA revised its methodology for calculating the window-sticker fuel-economy value for new vehicles. In order to make the data for previous model years comparable with model year 2017 (and future model years), the EPA also retroactively revised the corresponding data for some vehicles in model years 2011 to 2016.

Compared with October 2007, fuel economy ratings on new cars sold has improved by 4.8 miles per gallon, or about 24%.

While the window sticker average is 4.8 mpg higher than when the data were first collected, the average is still 0.6 mpg below its revised all-time high of 25.5 mpg set in August 2014. When gasoline prices started dropping in the United States, consumers purchased more light trucks, sport utility vehicles and crossovers, which get lower mpg ratings and drive down the average.

The data are based on the average sales-weighted fuel-economy rating printed on a new car’s window sticker and is compiled by Michael Sivak and Brandon Schoettle of the University of Michigan’s Transportation Research Institute.

The sales-weighted unadjusted Corporate Average Fuel Economy (CAFE) performance rating averaged 31.2 miles per gallon in December, down by 0.1 mpg month-over-month and an improvement of 6.5 mpg since October 2007. These values are not directly comparable to the window-sticker ratings because these are adjusted by the EPA and used to derive the window-sticker ratings.

U.S. auto sales in 2016 were up 0.3% year over year at a record 17.54 million units, compared with 17.48 million units sold in 2015. On a seasonally adjusted annual rate (SAAR) basis, the total jumped from 17.83 million units in November to 18.38 million units in December, the highest level of the year. New car prices posted an all-time high in 2016 and are forecast to rise another 2.7% in 2017.