As the industry’s leading diesel magazine, we like to present an image of jaded professionalism, especially when it comes to new trucks. A diesel-powered Chevrolet Colorado? We can easily evaluate it with the detached objectivity that such a significant new product deserves.
The 2016 Chevrolet Colorado is the first diesel-powered compact pickup the US market has seen in nearly thirty years—at least, the first one built by a factory as opposed to an intrepid Diesel World reader. We couldn’t wait to get behind the wheel, and we’re happy to say that the new Colorado did not disappoint.
DRIVING THE DOWNSIZED DURAMAX
We’ll take a deeper dive into the engine in a moment, but for now, here are a few numbers: Four cylinders, 2.8 liters (169 cubic inches) two cams, sixteen valves, 40 psi of boost, 181 horsepower and 369 lb-ft. of torque.
The Duramax-powered Colorado feels pretty much like any other stock diesel truck, but in a significantly smaller package. The torque curve is broad and flat, aided in no small part by a variable-geometry turbocharger, and the engine pulls cleanly and evenly. Unlike the Ram 1500 EcoDiesel, which is designed for quiet operation, Chevy wants you to know there’s a diesel under the hood. The engine makes its presence known throughout the lower speed ranges, though its four-cylinder clatter sounds more like a London taxi than a Cummins-powered big-rig. Out on the road, the engine settles down to a persistent thrum, which disappears behind a veil of road and wind noise above 60 MPH.
We didn’t have a chance to do full instrumented testing during our drive at a General Motors press preview, but according to our “butt dyno,” the Colorado might just edge out a Ram 1500 EcoDiesel at the strip.
READY FOR WORK
What clued us in to the diesel Colorado’s mission was the presence of a trailer-brake controller and an exhaust brake, both of which come standard with the Duramax engine (as does a hitch receiver and a seven-pin wiring connector). The four-cylinder Duramax isn’t just designed for fuel economy; it’s designed for work, just like its big brothers, albeit on a smaller scale.
“We weren’t looking to design an engine that was good on fuel economy but lacking in other areas,” explained Scott Yackley, assistant chief engineer for the 2.8-liter Duramax. “We were looking for overall integration: Best towing, best torque in the segment, and superior fuel economy, and a fun-to-drive feel. This engine was developed with trucks in mind from the beginning.”
The little Duramax diesel will tow 7,700 lbs. with two-wheel-drive and 7,600 with four-wheel-drive. We hooked up the Colorado to a two-ton trailer, which put a noticeable squat in the truck’s tail-high stance. While it doesn’t offer the stability of a 3/4 or 1-ton platform—what small pickup does? —the Colorado’s Duramax engine had no problem keeping up with traffic in the hills.
A single switch turns on both the six-speed automatic transmission’s tow/haul mode and the exhaust brake, which works by closing the vanes on the variable-geometry turbo (similar to the system used on the Duramax V8). Tow/haul mode downshifts aggressively when slowing to maximize exhaust braking, and when cruise control is engaged, the exhaust brake keeps the speed from creeping up on downgrades—another trick borrowed from the V8.
A 30-MPG PICKUP TRUCK?
So what about fuel economy? The EPA hadn’t released official numbers when we went to press (when they’re published, you’ll find them at FuelEconomy.gov) but the folks at GM alluded to a 30 MPG highway figure, 3-5 MPG better than gas-powered Colorados and 1 MPG higher than the Ram 1500 EcoDiesel.
Tooling through the hills near Santa Barbara, California, we saw around 24 MPG when running light; for comparison, the official EPA combined figures are 22 MPG for the gas four-cylinder Colorado and 21 MPG for the V6 (1 MPG lower with four-wheel-drive). We only saw around 15 MPG when towing, but we blame that on the terrain: Aside from one short highway sprint, we were towing on slow, curvy roads at low speeds that denied the transmission access to the higher gears.
DEEPER DIVE INTO THE DURAMAX
Now that you know how the baby Duramax drives, let’s open the hood and take a closer look at the hardware.
The 2.8L Duramax features common-rail injection, an iron block, aluminum heads, four valves per cylinder and a DOHC valvetrain. Turbocharging is handled by a water cooled VGT unit that is also (of course) intercooled. Output is 181 hp at 3,400 RPM and a stout 369 lb-ft. delivered at 2,000 RPM.
Among GM’s claims for the engine is that it is the cleanest diesel they’ve ever produced. The baby Duramax makes use of a cooled EGR system as well as exhaust after treatment. The diesel exhaust fluid (DEF) tank has a usable capacity of 5 gallons, which should give it a range to match the engine’s 7,500-mile oil-change interval. Like the Duramax V8, the four-cyl is certified to run biodiesel blends up to B20.
THE ITALIAN CONNECTION
Though the Duramax name implies a kinship to the V8 in the HD trucks, the two engines are similar in name only—in fact, one could argue that the four-cylinder Duramax is more closely related to Ram’s EcoDiesel. Like Ram’s 3.0 V6, the Duramax engine is based on a design from Italian engine manufacturer VM Motori. Before VM was acquired by Fiat (Chrysler’s parent company) General Motors was a 50% stakeholder in the company, and GM had a team stationed in-house at VM to help develop the engine, which is an offshoot of VM’s A428. (Another connection: The A428’s predecessor, the R428, can be found under the hood of the old Jeep Liberty CRD).
Though GM and VM have parted ways, the Duramax 2.8 isn’t an orphan: The tooling and design are wholly owned by General Motors, and the engine is built in a GM-owned plant in Thailand. GM is free to develop the engine for generations to come, which is exactly what they plan to do.
“We architected the exhaust after treatment system to handle future emissions regulations as they come up,” explained Yackley. The engine currently meets Federal Tier 2 Bin 5 and California ULEV125 standards. As for expected future changes, Yackley says, “We know what we have to do.”
HOW YOU CAN GET IT—AND WHAT IT WILL COST
GM will offer the diesel in LT and Z71 trims with a crew cab and choice of short or long box (128.3″ or 140.5″ wheelbase) and two- or four-wheel-drive. The engine comes exclusively with GM’s Hydra-Matic 6L50 six-speed automatic transmission and a 3.42:1 rear-axle ratio. The trans has been modified with a device GM calls the Centrifugal Pendulum Vibration Absorber (CPVA), which is integrated into the torque converter and reduces torsional vibration.
Chevy says the price jump for the Duramax diesel will be $3,730 over the gas V6—and don’t forget that the six costs $950 to $1,235 more than the base four-cylinder, depending on trim level. That means the diesel-powered Colorado will start around $33,500 including destination charge, with long-bed Z71 4x4s running closer to $36k—plus options, of course.
A BRIGHT FUTURE
Having driven the new diesel-powered Colorado, we’re excited about its prospects. We like that Chevrolet has outfitted this as a proper towing rig, with a hitch, wiring, and (especially) an exhaust brake. The Colorado has the hardware to tackle smaller jobs with the same skill as the Silverado HD tackles the big ones.
For now, the Colorado diesel has no true competitors (unless you count the Duramax-powered variant of the GMC Canyon, which is the same truck in a slightly different wrapper). The Toyota Tacoma, itself freshly redesigned for 2016, still owns the small-pickup market, but as far as we know, Toyota has no plans to offer a diesel version, at least not in this country.
Nissan did tease us at the 2014 Chicago Auto Show with the Frontier Diesel Runner concept, which is powered by a 2.8 liter four-cylinder Cummins ISF. Will that truck ever see production? Nissan isn’t saying—at least not now. They’re busy gearing up to launch the 2016 Titan XD, which is powered by a five-liter Cummins ISV V8.
(While we don’t have official numbers, we’ve heard from insiders that the diesel Titan will tow just about twice as much as the 2.8-liter Colorado, with low-end pricing about the same place where the high-end Colorado leaves off).
Overall, we really like the new diesel-powered Chevy Colorado—but we also know that the stock truck is just the beginning. We have no doubt that our friends in the aftermarket industry will take to the new baby Duramax like flies to honey, as will the racers, off-roaders, and the backyard engineers who read Diesel World. We’re excited by the new Duramax Colorado—but we’re even more excited to see what modifications are done to it and how it responds to them. DW