Pick-ups and SUVs are rapidly taking over the American automotive landscape, but there's at least one measure in which it benefits an automaker to sell fewer of those vehicles.

In the Environmental Protection Agency's latest "Light-Duty Automotive Technology, Carbon Dioxide Emissions, and Fuel Economy Trends" report released this month, Mazda was named as the automaker with the highest manufacturer adjusted fuel economy in America.

It's the the fifth straight year it has garnered the accolade.

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The report lags behind by one year, so the its current iteration shows fuel-economy data for 2016, when Mazda achieved a manufacturer adjusted fuel economy rating of 29.6 mpg (a 0.3 mpg increase over 2015).

But the achievement is a silver lining in a dark cloud for the Japanese automaker.

That year, the car-heavy product mix that made it possible for Mazda to win the competition also conspired to drive down its sales by 6.7 percent year over year, as more Americans moved to larger vehicles.

2016 Mazda CX-9

2016 Mazda CX-9

For comparison, the overall automotive market in the United States grew by 0.3 percent during 2016.

Those larger vehicles include mid- and full-size pickup trucks, which Mazda does not sell.

Mazda was closely followed by three other car-heavy automakers in the report: Hyundai, Honda, and Subaru scored from 28.8 to 27.9 mpg.

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Fiat-Chrysler unsurprisingly took the bottom slot in adjusted fuel economy, with a rating of 21.5 mpg, mostly due to a model mix rich in hot-selling SUVs and trucks but lacking smaller cars.

Ford and General Motors landed just above FCA at 22.8 and 22.4 mpg, respectively.

The EPA calculates manufacturers' adjusted fuel economy by finding the average of all models sold during a year and weighting the average based on sales for each model.

2016 Mazda CX-5 Grand Touring AWD, Catskill Mountains, New York, May 2015

2016 Mazda CX-5 Grand Touring AWD, Catskill Mountains, New York, May 2015

The adjusted numbers for each model are similar to the numbers printed on new-vehicle window stickers.

For more details on the performance of other automakers in the United States and other fuel-economy trends, you can view the report on the EPA website.

It's worth noting, of course, that Tesla was the sole maker in 2016 to sell only electric cars; because it has no cars that use "fuel," it was not formally part of the fuel-efficiency competition.

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