General Motors announced Tuesday that it will introduce a new turbo-diesel Duramax engine for its and midsize pickup trucks this fall, calling it the cleanest diesel truck engine ever produced by the automaker.

The 2.8-litre Duramax four-cylinder will generate 181 horsepower and 396 lb-ft of torque and up the trucks' trailering capacity to 7,700 lbs (3,492 kg) on 2WD models, from the gas trucks' 7,000 lbs.

Gm also says fuel economy estimates are better than the gasoline-engined Colorado and Canyon's 27 mpg (8.7 L/100 km) average (for the 2.5-litre with automatic trans), which are already best-in-class.

Thanks to several new technologies, the Duramax four-cylinder is also the cleanest diesel truck engine that GM has ever produced.

The Duramax diesel will be available in 2WD or 4WD variants, but only in LT and Z71 Crew Cab trims of the Colorado and SLE and SLT Crew Cab trims of Canyon. The engine will cost $3,730 more than the V6 (in the U.S.) and go on sale fall 2015.

The Colorado and Canyone were reintroduced into the North American for the 2015 model year after being discontinued following the 2012 model year .