Each month, the University of Michigan Transportation Research Institute looks at monthly vehicle sales, and uses the cars' window stickers to provide a rough look at our average new-car fuel economy. For the month of August, we're back down again, hitting a level not seen since April.
Last month's sales-weighted average fuel economy was 25.3 mpg, according to UMTRI researchers Michael Sivak and Brandon Schoettle. That is down from the previous month, but only by 0.1 mpg. In fact, we've been hovering in the 25s since January 2014. Since then, our highest month was August 2014, with 25.8 mpg. The lowest point came in December 2014 and 2015, at 25.0 mpg.
The general trend is upward, but even with all the advancements in engine tech over the past couple years, we've hit a point of stagnation. This likely coincides with lower gas prices, which spur buyers to go out and buy thirstier vehicles, because nobody seems to realize that gas prices will eventually rise again.
If last year's trends are any indicator, we're not going to see much progress until warm weather comes back in 2017. For the last two years, average fuel economy has dropped through the winter, only to pop back up when the ground starts thawing. In fact, for the last five months, our average fuel economy is exactly the same as it was in 2015. Now that's progress!