ANN ARBOR, Michigan — After holding steady for two months, the average fuel economy for new cars sold in August dropped to 25.3 mpg, according to researchers Michael Sivak and Brandon Schoettle of the University of Michigan Transportation Research Institute.
The August average is down 0.1 mpg from that in June and July, and down 0.5 mpg from the peak reached in August 2014, but still a significant improvement of 5.2 mpg from October 2007 when the researchers first began compiling data.
The latest UMTRI Eco-Driving Index stands at 0.82, indicating that the average new-vehicle driver produced 18 percent lower emissions than in October 2007, although that number is 4 percent higher than the record low reached in August 2014.
To arrive at its figures, UMTRI calculates average sales-weighted fuel economy from the monthly sales of light-duty vehicles (cars, SUVs, vans and pickups) and the combined city/highway fuel economy ratings that appear in the EPA Fuel Economy Guide and on vehicle window stickers.
According to UMTRI, the decline in average fuel economy "likely reflects the decreased price of gasoline in August, and the consequent increased sales of light trucks and SUVs."
As recently reported by Edmunds, last month's sales leaders included SUVs like the Acura RDX, Buick Encore, Chevrolet Equinox, Ford Edge, Infiniti QX60, Jeep Compass, Lincoln Navigator and Nissan Rogue, as well as pickup trucks, including the Chevrolet Silverado, Ford F-Series and Toyota Tacoma.
According to the AAA Daily Fuel Gauge Report, the average price of a gallon of regular unleaded gasoline nationwide was $2.42 on Friday, versus $3.43 a year ago.
AAA found that the Pacific Northwest is the country's most expensive region for fuel and also noted that all of the top 10 priciest states for gas are located west of the Rockies. At the other end of the spectrum, motorists in South Carolina are paying the lowest pump prices in the nation.
On average, according to AAA, U.S. drivers can look forward to the lowest Labor Day fuel prices since 2004.
Edmunds says: The strong sales of SUVs and trucks, which are affecting average fuel economy, suggest that consumers are taking advantage of relatively low gas prices.