In April, new vehicles averaged 25.3 miles per gallon, according to the University of Michigan Transportation Research Institute's (UMTRI) Michael Sivak and Brandon Schoettle.
That number for April 2017 is up 0.1 mpg from March. It equals last May's figure, and is tied for the highest fuel economy since fleetwide numbers reached an all-time record 25.5 mpg in August 2014.
The increase may reflect the boost in sales for advanced-powertrain vehicles such as hybrids and plug-ins. Last month, US sales of such vehicles were up about 6.5 percent from a year earlier to about 38,000 units, while plug-in sales alone surged approximately 33 percent. A monthly record 1,292 Chevrolet Bolt electric vehicles were sold while Tesla continues to increase its deliveries of electric vehicles each quarter. Throughout the first four months of the year, US sales of hybrids and plug-ins have jumped about 18 percent from a year earlier.
The uptick may also reflect slightly higher gas prices. At the end of April, US fuel prices averaged about $2.39 a gallon, which was up about 8 percent from a year earlier, according to AAA. Notably, last month's sales of Ford's world-beating F-Series pickup trucks actually dropped slightly from a year earlier after advancing 10 percent for the first three months of the year. Ford's April sales of almost 71,000 F-Series trucks were still almost double sales of hybrids and plug-ins from all automakers combined.
Last year was the third straight year model-year fleetwide fuel economy checked in at 25.1 mpg.