The average fuel economy of new U.S. trucks, cars, SUVs and vans sold in January rose 0.1 mpg from December, to 24.9 mpg, according to a monthly report from the University of Michigan Transportation Research Institute.
The average fuel economy of new vehicles sold in the United States is up 4.8 mpg since the researchers began collecting data in October 2007.
Average sales-weighted fuel economy was calculated from the monthly sales of individual models and the combined city-highway fuel economy ratings from the EPA Fuel Economy Guide for each model.
Meanwhile, the institute's national Eco-Driving Index, which calculates the monthly greenhouse gas emissions from a U.S. driver who bought a new vehicle during the month, fell to a record-low 0.79 in November. A lower index score is better, and the scores are compared with a base score of 1 in October 2007, when the researchers began collecting data.
"This value indicates an improvement of 21 percent since October 2007," researcher Michael Sivak said in a statement. "The EDI takes into account both the fuel used per distance driven and the amount of driving."