Seven Details that Make the 2017 Chevrolet Colorado ZR2 Special
The key building blocks of Chevy’s midsize off-road pickup
Earlier this week, I had the pleasure of driving the 2017 Chevrolet Colorado ZR2 through the Rocky Mountains outside Grand Junction, Colorado. I'm not allowed to tell you how it drives until Monday, May 15, but to whet your appetite, here's a look at seven details that give this midsize pickup its off-road chops.
1. Dynamic Suspensions Spool Valve (DSSV) dampers
First used by GM on the 2014 Camaro Z/28, the DSSV dampers are the most important part of the ZR2's kit. Initially developed by Canadian supplier Multimatic for use in ChampCar, DSSV dampers were used by Red Bull in its F1's championship-winning cars and have served duty in numerous other racing applications, as well as a growing number of high-performance street cars including the Aston Martin One-77.
The use of spool valves, which operate in a predictable and precise manner instead of traditional shim valves, allows engineers to more accurately tune the damper settings with far less variation in behavior due to temperature and suspension response frequency, which varies with speed and road conditions.
While the Z/28's dampers use twin piston-mounted spool valves, which allow independent tuning of compression and rebound characteristics, Multimatic moved the two valves into an external reservoir and added a third valve within the piston for use in the Colorado ZR2, the first off-road application of the technology.
The third valve creates a position-sensitive damper, much like those typically used in dedicated off-road vehicles, while moving the twin valves to a reservoir allows for greater piston travel. The practical effect is a setup that is said to blend excellent off-road performance with a smooth and compliant ride on-road.
2. Front and rear electronic locking differentials
Because the Colorado ZR2 is meant to (rock) crawl as well as (desert) run, Chevrolet outfitted the truck with class-exclusive front and rear Eaton electronic locking differentials (its closest rival, the Toyota Tacoma TRD Pro, only offers a rear locker). Activated with the press of a button on the center console, the lockers enable the ZR2 to mountain goat over even more challenging obstacles.
FCA is the only other automaker to offer a front locking differential, fitting one on the Ram Power Wagon and Jeep Wrangler Rubicon. But neither solid front axle-equipped rig is well-suited for high-speed desert runs, and the full-size Power Wagon won't be able to make its way down tighter trails.
3. Extensive underbody protection
Because you won't make it far down the trail if you crack your oil pan against a rock, Chevrolet equipped the ZR2 with a pair of aluminum skid plates under the engine to protect the oil pan and radiator, a separate plate protecting the transfer case, and steel rocker sliders. Though body- instead of frame-mounted, the tubular sliders are more than capable of protecting the vulnerable rockers from impacts and allow the truck's body to be dragged across a surface without any damage.
4. Wider track
The Colorado ZR2 features a 3.5-inch wider track than the rest of the lineup. Chevrolet simply didn't use spacers to add the extra width, either. Instead, it went with a wider axle and new cast-iron control arms. (Also supplied by Multimatic, these feature a neat Easter egg: a ZR2 badge cast into the top.)
While the extra track slightly reduces the width of the trails the ZR2 can tackle, it gives the truck greater wheel travel — the ZR2 boasts 8.6 inches of suspension travel up front and 10.0 inches at rear — and improves stability, both at high speeds and while traversing steep grades.
5. Unique front end and rear bumper
Because it would be a missed opportunity to create a purpose-built truck but leave it looking the same, Chevrolet fitted the ZR2 with a unique front end that features a tapered front bumper, more aggressive grille, and a new hood with a black insert.
In addition to giving the ZR2 a distinctive look, the revised front end provides it with an improved approach angle of 30 degrees. Chevy's engineers, however, mentioned that the ZR2 can conquer even steeper approaches thanks to its front locker and skid plates. That is, as long as the driver is able to get a wheel up onto the obstacle.
There's a new rear bumper as well. It dispenses with the corner steps seen on the standard Colorado, which were frequently crushed by off-road obstacles during development.
Further, the ZR2 can be fitted with a bed-mounted spare tire carrier, which improves the departure angle by relocating the spare tire. Alternatively, it allows the ZR2 to carry two spares instead of one without any additional equipment. It also looks pretty cool.
6. Increased ground clearance
Thanks to the combination of the DSSV dampers and 31-inch Goodyear Duratrac tires, the ZR2 sits 2 inches higher than other 4WD Colorados, giving it an ample 8.9 inches of ground clearance and the ability to ford up to 26 inches of water. Additionally, the ZR2 boasts breakover and departure angles of 23.5 degrees.
7. Optional diesel I-4
In addition to being the only vehicle on the market with an independent front suspension mated to a front locker, the Colorado ZR2 is also the only one that can be had with a diesel engine. It's the same Duramax 2.8-liter I-4 offered in the rest of the Colorado lineup, putting down 181 hp and 369 lb-ft of torque sent through a six-speed automatic transmission.
If you're not sure how this is of benefit to off-roaders, there's a simple, four-word explanation: copious low-end torque. The last thing you want to do while trying to navigate a rocky face is mash the throttle; with the diesel, you'll never have to. You'll also be able to go much farther before reaching for the nearest jerrican.