General Motors promised a diesel when it announced its return to the smaller pickup market, and a year after the Chevrolet Colorado and GMC Canyon re-launched as 2015 models, the engine is ready to go. GM’s new 2.8-liter Duramax will be available in the 2016 Colorado/Canyon by the end 2015, and it’s no boat anchor.
With an aluminum cylinder head, forged steel rods and crank, 16.5:1 compression and common-rail direct injection operating at up to 29,000 psi, this truck-specific, 2.8-liter turbodiesel four generates 181 hp at 3,400 rpm, and 369 lb-ft of torque at 2,000. At least 330 lb-ft are available between 1,400 and 2,900 rpm.
How far has mainstream automotive technology come in 30 years? The last diesel offered in a small U.S. Chevy truck—the 1985 S-10—was built by Isuzu. At 2.2 liters, it made 62 hp and 96 lb-ft. The contemporary Ford Ranger offered a diesel through 1987. That was a 2.3-liter turbo from Mitsubishi, and it generated 86 hp and a whopping 134 lb-ft.
The Duramax 2.8-liter turbodiesel four cranks out 181 hp and 369 lb-ft of torque.
The stand-out bit of tech in the 2.8-liter Duramax might be its liquid-cooled, variable-geometry turbocharger, with a little electric motor that varies the diameter of the impellor. Once reserved for Freightliners and Porsche 911 Turbos, VGTs operate with minimal lag in single-turbo applications. They have a low boost threshold and are particularly efficient at higher engine speeds. In the 2.8L Duramax, the VGT generates up to 40 PSI of boost, but requires no waste gate.
It also enables GM’s Exhaust Brake system, which operates like a Jake brake and has been lauded for the confidence it gives drivers pulling or carrying heavy loads.
The 2.8-liter Duramax was developed by GM Powertrain in Pontiac, Michigan, and Rüsselsheim, Germany. The basic design has been in production since 2011, primarily for small pickups sold in Southeast Asia and South America. Application in North America prompted another round of development and a second generation, focused on adaptation for climate extremes and better NVH control.
New-for-2015 Chevrolet Colorado sees addition of diesel power for 2016
For the North American Colorado and Canyon, the 2.8-liter Duramax gets faster-heating ceramic glow plugs, a more potent starter motor and a plug-in AC block heater. It has strategic noise deflectors and a big foam slab under its acoustic engine cover, and it’s fitted with dual gear-driven balance shafts.
GM’s Hydramatic 6L50 automatic, the only transmission offered with the 2.8-liter Duramax, is also equipped with something GM Powertrain calls CPA--for centrifugal pendulum absorber. CPA is essentially an electronically managed, spring-actuated clutch in the torque convertor. It closes or releases in milliseconds to counter-balance quick variations in torque and minimize lash through the transmission, driveshaft and rear end.
You have to go all the way back to 1985 to find the last diesel-powered compact Chevrolet pickup sold in the U.S.
The 2.8-liter Duramax will be 50-state compliant with owner-added urea for exhaust after-treatment. It will be built in Rayong, Thailand, and shipped to the Colorado/Canyon assembly plant in Wentzville, Missouri.
The diesel will be offered in Colorado and Canyon crew cabs, mid-trim and up, with two-or four-wheel-drive. Official ratings are pending, but GM expects the highest mileage in its smaller pickup line and a higher max tow-rating than the current upgrade 3.6-liter gasoline V6 (305-hp, 269 lb-ft).
The company estimates a 10 percent take-rate for the 2.8L Duramax, but it’s protecting itself for higher demand, and it should. In full-size trucks, diesel sales have increased faster than pickup sales as a whole, and diesel customers tend to choose heavily optioned, high-sticker models.
We’re not talking stripper S-10s.
