Well, here's a bit of good news.

The sales-weighted average gas mileage for all vehicles sold in the U.S. was the highest it's ever been, reaching 22.9 miles per gallon.

That's almost 1 mpg higher than the 22.0 mpg figure for January 2011, according to an analysis by TrueCar.

While 22.9 mpg may not sound all that high, remember that more than 100,000 full-size pickup trucks and sport-utility vehicles are sold each month.

Their gas-mileage ratings, usually well below 20 mpg, drag down the average, offsetting subcompact and compact cars and hybrid vehicles that have far higher EPA fuel economy ratings.

The full breakdown can be found on TrueCar's blog, but a few individual statistics stand out for January sales.

First, Asian car brands (Toyota, Nissan, Hyundai, and Honda, in that order) take the top four sales-weighted average mileage positions, followed by General Motors, Ford, and then Chrysler.

Of the seven best-selling brands, Toyota is best, at 24.6 mpg; Chrysler--which sells the highest percentage of light trucks of the seven--brings up the rear at 19.5 mpg.

Toyota and Hyundai are almost tied, at 29.5 mpg and 29.3 mpg respectively, for highest average miles in cars alone. Chrysler lags severely at 22.6 mpg.

In trucks (which include crossovers and minivans), Hyundai leads at 23.5 mpg and GM and Toyota are tied for last place, at 17.7 mpg.

The ratings are calculated using what TrueCar calls "TrueMPG," which multiplies Environmental Protection Agency (EPA) gas-mileage ratings by the estimated and/or actual monthly sales for each model.

Realistically, fuel economy will continue to increase slowly from now through 2025.

The increase is not driven by consumer willingness to pay for more fuel-efficient vehicles--consumers, by and large, don't want to pay much for higher MPGs--but by rules adopted jointly by the EPA and the NHTSA in 2009 for corporate average fuel economy standards for 2012-2016 model-year cars.

The EPA recently held public hearings on its proposed rules for the 2017-2025 period, and is expected to issue those final rules this year.


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