2015 Ford F-150 Gas Mileage: Best Among Gasoline Trucks, But Ram Diesel Still Highest

Perhaps no gas-mileage ratings have been as eagerly awaited this fall as those for the all-new 2015 Ford F-150 pickup.

The redesigned full-size truck with an aluminum body and pickup bed was expected to get better gas-mileage numbers than earlier F-150s.

And it has, with a top rating of 22 mpg combined (19 mpg city, 26 mpg highway) for the most fuel-efficient model, a rear-wheel-drive model with the new 2.7-liter EcoBoost V-6 engine.

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But the F-150's best rating falls shy of the most fuel-efficient full-size pickup on sale, the 2015 Ram 1500 EcoDiesel--rated at 23 mpg combined (20 mpg city, 28 mpg highway) in rear-wheel-drive form.

The diesel Ram 1500 has been remarkably successful for Fiat Chrysler; it will soon make up fully 20 percent of production.

The 2015 Ford F-150 fuel-economy numbers vary across a wide range of models, so here's the full lineup:

• Rear-wheel drive, 2.7-liter EcoBoost V-6: 22 mpg combined (19 mpg city, 26 mpg highway)

• Rear-wheel drive, 3.5-liter V-6: 20 mpg combined (18 mpg city, 25 mpg highway)

• Four-wheel drive, 2.7-liter EcoBoost V-6: : 20 mpg combined (18 mpg city, 23 mpg highway)

• Rear-wheel drive, 3.5-liter EcoBoost V-6: : 20 mpg combined (17 mpg city, 24 mpg highway)

• Four-wheel drive, 3.5-liter EcoBoost V-6: : 19 mpg combined (17 mpg city, 23 mpg highway)

• Four-wheel drive, 3.5-liter V-6: 19 mpg combined (17 mpg city, 23 mpg highway)

• Rear-wheel drive, 5.0-liter V-8: 18 mpg combined (15 mpg city, 22 mpg highway)

• Four-wheel drive, 5.0-liter V-8: 17 mpg combined (15 mpg city, 21 mpg highway)

(All versions use a six-speed automatic, although a new 10-speed transmission will be introduced in a year or two--which should boost each of these ratings by 1 to 3 mpg.)

Not all of the new F-150's ratings can be directly compared to last year's models. For one thing, the 2.7-liter EcoBoost V-6 is an all-new engine.

While the 5.0-liter V-8 and 3.5-liter EcoBoost V-6 are carryovers, the 3.5-liter (non-turbo) V-6 is a slightly lower-displacement version of last year's 3.7-liter V-6.

Ford said in its media release that the 2015 F-150's EPA ratings are "5 to 29 percent better" than comparable 2014 models.

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Using the V-8 engine as a comparison, the effect of the lighter-weight aluminum truck seems to be relatively small.