Lower gas prices, leading to an increase in the sales of gas-guzzling light trucks and sport utility vehicles, is the likely culprit behind a dip in the average fuel economy of new vehicles sold in the United States last month.
The average fuel economy (window-sticker value) was 25.4 mpg in June, down 0.1 mpg from May. Fuel economy is down 0.4 mpg from the peak reached in August 2014.
However, vehicle fuel economy is up 5.3 mpg since October 2007, the first month that the University of Michigan Transportation Research Institute began tracking it.
The average monthly emissions of greenhouse gases generated by individual drivers also was up slightly in April, 0.85, compared to March (0.82). Emissions are 15 percent lower nowadays than they were eight years ago, but they’ve gone up 9 percent since reaching a record low in August 2014.