The 2016 Chevrolet Colorado and GMC Canyon mid-size pickup twins, fitted with the newly-available Duramax four-cylinder diesel engine, are now the most fuel-efficient pickup trucks sold in the U.S.

EPA fuel-economy ratings are in, and rear-wheel-drive versions of the General Motors trucks are rated at 25 mpg combined (22 mpg city, 31 mpg highway).

That edges out the full-size Ram 1500 EcoDiesel HFE, which is rated at 24 mpg combined (21 mpg city, 29 mpg highway) in rear-wheel-drive form.

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With four-wheel drive, the Colorado and Canyon diesels are rated at 23 mpg combined (20 mpg city, 29 mpg highway).

That beats the four-wheel drive Ram 1500 EcoDiesel as well; its numbers are 22 mpg combined (19 mpg city, 27 mpg highway).

The GM twins also handily outdo the only other mid-size trucks currently sold in the U.S.--the Toyota Tacoma and Nissan Frontier.

2016 Chevrolet Colorado Duramax diesel

2016 Chevrolet Colorado Duramax diesel

Revamped for 2016, the Tacoma gets 21 mpg combined (19 mpg city, 24 mpg highway) in its most fuel-efficient guise: rear-wheel drive with a 3.5-liter V-6 and six-speed automatic transmission.

The Nissan hasn't been updated for some time, and musters a best 21 mpg combined (19 mpg city, 23 mpg highway) with a 2.5-liter four-cylinder engine, rear-wheel drive, and a five-speed manual transmission.

The GM 2.8-liter turbocharged diesel four-cylinder Duramax engine produces 181 horsepower and 369 pound-feet of torque, and is offered only with a six-speed automatic transmission.

ALSO SEE: 2015 Chevrolet Colorado, GMC Canyon Four-Cylinder Gas Mileage: 21 Or 22 MPG Combined (Sep 2014)

GM will continue to offer a 2.5-liter four-cylinder and 3.6-liter V-6 gasoline engines alongside the diesel.

In addition to the fuel-economy ratings themselves, GM notes, the EPA also issued a "certificate of conformity" that states the agency has no issues or concerns with the emissions-control systems on the GM trucks.

It's a rare bit of good news for new diesel vehicles in the midst of the ongoing Volkswagen emissions scandal.

2016 GMC Canyon

2016 GMC Canyon

Despite the apparent damage to diesel's reputation in Volkswagen and Audi passenger cars, GM will reportedly move ahead with plans to offer more diesels in the U.S.

A previously-announced diesel version of the redesigned Chevrolet Cruze is still slated to launch on schedule for the 2017 model year, GM product chief Mark Reuss told a gathering of auto journalists in Detroit yesterday.

MORE: 2016 Chevy Colorado Diesel Pickup Priced At $31,700; Fuel Efficiency To Come Later

Meanwhile, the Colorado and Canyon diesels will go on sale before the end of this year, GM says.

The diesel option will be priced at $3,730 more than the 3.6-liter gasoline V-6, making the Duramax the priciest engine in the lineup.


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