The Duramax has been an eagerly awaited addition to the Colorado lineup since it was announced in 2014. In the meantime, sales of gasoline-fueled Colorados have surpassed expectations, and GM's plant has been running flat-out to keep up. The addition of the Duramax variant's pent-up demand will only exacerbate this supply constraint, so don't be surprised if you have to wait to take delivery of one.
What's New Under the Hood?
Though the Colorado's 2.8-liter inline-four-cylinder turbodiesel is new to the U.S. market, this engine has seen duty in many global markets for several years. So despite its newness Stateside, the new engine is a well-honed, mature product.
Changes were made to suit the U.S. market, however, since we expect a certain level of refinement and have more stringent emissions requirements than other regions. As such, the engine received a host of noise- and vibration-abatement measures, a urea-based exhaust after-treatment system and a revised engine calibration.
The result is a four-cylinder engine that generates 181 horsepower at 3,400 rpm. No news there. The kicker is the torque. There's 369 pound-feet of it and it peaks at 2,000 rpm. Compare that to the 3.6-liter gasoline V6, which delivers far more horsepower (305) but only 269 lb-ft of torque at 4,000 rpm.
A smaller compressor wheel in the diesel's variable-nozzle turbo improves response and enhances performance at altitude. Vibrations are smoothed out by balance shafts within the beefy iron block and a pendulum absorber in the six-speed automatic's torque converter, while Denso solenoid injectors are programmed to exorcise diesel clatter.
This is a purpose-built truck engine, and the engineering team accordingly subjected it to the same battery of testing levied upon all GM truck engines. The engine's robustness is partly why diesel-equipped Colorados weigh between 260 and 300 pounds more than otherwise similar V6-equipped models.
For towing, the Duramax is tops among Colorados. Chevrolet pegs the diesel's tow rating at 7,700 pounds (7,600 for 4WD versions). This is 700 pounds more (600 pounds for 4WD models) than the V6 Colorado equipped with the optional Trailering package. Payload capacity drops a few dozen pounds relative to V6 Colorados to between 1,457 and 1,508 pounds for the diesel.
What Else Is New?
The truck itself is fundamentally carried over intact from the existing model. But that's not to say the diesel engine was plopped in and the truck sent on its way with no other changes.
The engine's additional mass necessitated revisions to the suspension tuning and a revised calibration for the electric power steering system. The diesel setup also includes a driver-selectable exhaust brake that closes the turbocharger's vanes to provide engine braking.
How Does It Drive?
Rolling into the Duramax's right pedal from a stop produces intuitive, linear motivation. There's little of the off-boost sogginess you might expect from a turbodiesel. Torque at full whack is certainly healthy in the low- to midrange, and the engine feels perhaps a touch brighter than its 181 hp rating would suggest.
A welcome side effect of the broad torque delivery on tap is a reduction of the irksome transmission hunting that we've observed in our V6-powered long-term Colorado. Motoring in the diesel just feels breezier.
Turbo noise is almost nonexistent. In fact, most of the telltales of the diesel combustion are effectively banished once the truck's speed surpasses 20 mph or so. At idle or with the windows down, the engine's diesel-ness tips its hand — you notice a quiver at idle and the characteristic diesel grumble during light load operation — but it's never offensive.
Scott Yackley, the engine's assistant chief engineer, acknowledges that the engine might be too quiet for die-hard diesel enthusiasts who want to revel in the noise. For those customers, he says half-jokingly, the solution is free and easy: Simply remove the sound-damping blanket that sits atop the engine.
As far as handling is concerned, the additional mass lurking over the front wheels is unmistakable, but the stiffer springs ensure that it always remains in control. Another seat-of-the-pants difference includes a firmer brake pedal during light braking compared to what's found in the gasoline versions of this pickup. On a dirt ranch path, we also sampled the truck's hill descent control feature and give it high marks for its smooth operation and lack of histrionics.
What's the Interior Like and What Features Are Available?
Diesel models come standard with a 3.42 axle ratio, a trailering package including an integrated trailer brake controller, plus the aforementioned exhaust brake incorporated into the Tow/Haul button. All Colorados offer Apple CarPlay compatibility for 2016, and LT and Z71 models receive an improved gauge cluster screen.
Elsewhere, the interior is carried over intact from the current Colorado, and we've found it a mixed bag when compared to the cabin of its bigger brother, the Silverado. The backseat in particular lacks versatility with its cramped underseat storage and tall stack height when the seatback is folded.
How Much Does It Cost?
The diesel engine adds a not-inconsiderable $3,730 to the sticker over a comparably configured V6 model, bringing the Duramax's minimum price of entry to just under $36,000. While the diesel is certain to deliver the best fuel economy of any midsize pickup, thus eventually offsetting the engine's premium, GM hasn't released the truck's EPA fuel economy numbers.
Based on hints from GM and our drive, we are confident that the Duramax's combined mpg will be comfortably in the mid-20s and its highway rating will surpass 30 mpg. By comparison, the 2WD V6 Colorado manages 20 mpg in combined driving (21 combined mpg for 4WD V6 models).
What Competing Models Should You Also Consider?
Ram 1500 Ecodiesel: Bigger and priced a bit higher than the Colorado Duramax, the half-ton Ecodiesel is the next rung up the diesel truck ladder.
Toyota Tacoma: The Tacoma was redesigned for 2016. However, there's still no diesel offered, which is a shame considering Toyota has been offering one in overseas markets for decades.
Why Should You Consider This Truck?
There's simply no other alternative to the Colorado Duramax if you want a diesel-powered midsize pickup, and GM's turbodiesel engine is a sharp performer besides. It's refined, has good manners and is less frenetic than the gasoline V6 model.
Why Should You Think Twice About This Truck?
It's only available in crew cab configurations with select trim levels. That also means it's expensive.
Edmunds attended a manufacturer-sponsored event, to which selected members of the press were invited, to facilitate this report.
