The average (window sticker) fuel economy value of new vehicles sold in the U.S. in July was 24.8 mpg, which is an 0.1-increase from June and ties the record high reached earlier this year in March, April, and May, according to research by Dr. Michael Sivak and Brandon Schoettle from the University of Michigan's Transportation Research Institute (UMTRI).

New vehicle fuel economy is up 4.7 mpg since Oct. 2007, according to researchers. The average fuel economy of MY-2013 vehicles sold so far, from Oct. 2012 through July 2013, is 24.7 mpg, which is up 1.2 mpg from MY-2012 vehicles, according to the researchers.

The University of Michigan’s Eco-Driving Index, which estimates the average monthly greenhouse gas emissions generated by an individual U.S. driver, was 0.81 in April (a lower value means fewer emissions). This value represents a 19 percent improvement since Oct. 2007. The EDI takes into account the amount of fuel used per distance driven and the amount of driving.