According to the University of Michigan Transportation Research Institute, the average fuel economy of new vehicles in the U.S. based on their window sticker values remained at 25.3 mpg in September, unchanged from August.
Overall, fuel economy ratings remained down 0.2 mpg from a peak of 25.5 mpg in August 2014 and up 5.2 mpg from a low of 20.1 mpg recorded when monitoring began in October 2007.
The University of Michigan Eco-Driving Index (EDI) was 0.81 in July, down from 0.83 in June. The index estimates the average amount of greenhouse gas emissions generated by U.S. drivers on a monthly basis, with lower values indicating better performance.
Taking into consideration a combination of fuel economy and driving distance, the EDI value indicates that on average, new-vehicle drivers produced 19% lower emissions in July compared to October 2007, but 3% more than a record low last reached in November 2013.