My dad and I went to Miatas At The Gap when I was nineteen. I had just purchased one of my own, and in spending a few days around countless people obsessed with the cars, we got to talking about suspension upgrades. “It’s all about the bumpstops, man, you gotta have the right bumpstops” is a line that I remember to this day, from one man who had supposedly tested a variety of them in search of the perfect ride. The memory flooded back as I took the wheel of the Chevy Colorado ZR2 Bison and later, the Chevy Silverado 2500 ZR2 Bison.
Bumpstops are but one part of the whole ZR2 Bison equation, but Chevy had me out to Palm Springs, California to see what the ZR2 Bison trucks could do in their element – the desert. We ended up about an hour north of the fabulous, mid-century modern town at Johnson Valley, home to the famed King of the Hammers race.
Despite taking various vehicles off-road at home, I’m more of a novice than a pro. The Washington, D.C. metro area only offers a few trails within a couple hours’ drive, and they ultimately aren’t that challenging if your truck or SUV has serious off-road chops. As an example, I had never aired down my tires before hitting a trail, something the Chevy engineers handled to give us the best traction on higher-speed dirt and the most flex on rocky trails.
Meeting the Bisons: 2024 Colorado ZR2 Bison & 2024 Silverado 2500 ZR2 Bison
Chevy partners with American Expedition Vehicles (AEV) to create the Bison package for their trucks, and it’s available on all three in the lineup – Colorado, Silverado 1500, and Silverado 2500. Where ZR2 is developed in-house and indeed plenty capable on its own, adding the Bison trim provides a few additional goodies that you may find advantageous if you spend more time off the asphalt than on it.
First up, the Colorado ZR2. Picking the ZR2 trim gives you the 2.7-liter turbo four in its High Output guise, with 310 horsepower and 430 lb-ft of torque. You’ll also find the highest-riding suspension of all Colorados, sitting three inches taller than a base Colorado W/T. Peeking past the 17-inch wheels with 33-inch tires, you’ll see triple-reservoir Multimatic DSSV dampers that use a spool valve to provide speed-sensitive control but with far more nuance over a regular piston-and-shim sort of shock. Front and rear lockers are included, as are rock sliders, a front skid plate, a transfer case shield, and bumpers that offer better approach and departure angles than “lesser” Colorados.
Choosing the Bison package for your Colorado ZR2 will add unique AEV bumpers, with the front being ‘winch-ready,’ stronger boron steel skid plates and rocker protection, and unique 17-inch wheels that are half an inch wider with a 35-inch tire on ’em. A bed-mounted spare is added – blocking your rear-view mirror in the name of easy trail use. Most importantly, though, are the bumpstops, man. The Colorado ZR2 Bison has special “jounce control dampers” by Multimatic that work in lieu of a traditional bumpstop. More on those in a bit.
Moving to the Silverado 2500 ZR2, Chevy has managed to give their big-ish (there are bigger) pickup the ZR2 treatment about as effectively as they could. It’s lifted 1.5 inches over other Silverado 2500s and also gets those fancy Multimatic DSSV dampers. They’re tuned for either V8 engine choice, the standard 6.6-liter gasser or optional 6.6-liter Duramax diesel. Why the re-tuning? The Duramax adds 702 pounds to the nose of the truck, so re-calibrating the Multimatics and the springs was key. Otherwise, you’ll find larger-than-normal skid plates underneath alongside unique front control arms and steering knuckles. 35-inch Goodyear mud-terrain tires wrap around 18×9-inch wheels. A rear locker is included, though the front differential remains open.
Here the Bison package also adds unique bumpers with a front winch provision, stronger underbody skid plates (but no sliders) and unique 18-inch wheels. Those jounce control dampers from the Colorado ZR2 Bison aren’t used here, with Chevy employing regular bumpstops instead.
Rock-Crawling in the Colorado ZR2 Bison
My day started in the Colorado, and as we bounded along the desert I tested the higher compression damping and more controlled rebound of the jounce control dampers almost immediately. Through a series of whoops the truck stayed composed and comfortable, even when I found myself going “faster than ideal” for conditions.
“It’s an amazing little run here where you’re driving up to it and you think nope, this is not happening, and he’ll tell you ‘keep coming, keep coming’ and just do what he says.” Shad Balch, Director of Chevrolet Communications, was in the back seat of my Colorado and could not have spoken more true words as we approached the rocky… trail? It barely looked like a trail. I put the Colorado in Terrain mode, locked both differentials, and turned on the front-facing camera, then put all of my faith in Chevy’s spotters to guide me through the course.
The rocky trail used every piece of the Colorado ZR2 Bison’s hardware. Tires, ground clearance, lockers, suspension and sliders all played a part. Supposedly the jounce control dampers also help while rock crawling, and while I was mentally in a state of discomfort from the “you want me to drive over that rock with this and there’s a wall right here” moment, my body itself was indeed quite comfortable throughout the trail.
I never wanted for more torque, either, although getting used to the dulled throttle programming in Terrain mode took some time. I had to boot it a bit more than I felt was “right” to get the turbo to spool up; on the flip side, one-pedal driving was easy to master. Chevy uses an electric brake booster instead of a traditional hydraulic unit to make this trick feature work.
In no world was the rock crawl “easy.” It was far beyond my comfort level and a legitimate demo of the Colorado ZR2 Bison’s capabilities. Color me impressed.
Hill Descent in the Silverado 2500 ZR2 Bison
We changed trucks at a clearing and I was again a bit nervous. The Silverado 2500 is a big truck and despite the desert being… quite large itself, we were headed to another trail. This time we were going straight up on loose-ish sand, then mostly straight back down, again with plenty of rocks in our path.
Heading toward the second trail and chatting away with my co-driver Michael and Chevy rep Shad, I managed to hit some whoops at a speed far higher than anyone with eyeballs would attempt. Despite the lack of jounce control dampers (how many times can I use that phrase?) the 8,500-pound red truck slammed its way through the sudden challenge with relative grace. Some nervous laughter later, I locked the rear diff and pointed the Silverado’s nose skyward with some moderate throttle input up our hillclimb. The big 35s dug in, helped by the locked rear axle and low-range four-wheel drive gearing as we rode the Duramax’s 975 lb-ft wave of torque up the hill.
More challenging, however, was the descent. The sand gave way to rocks, and while we weren’t “rock crawling” as in the Colorado, you still had to choose a line and be careful getting down. Someone had ripped a power-folding running board off of my truck before I got in, and I watched as several other drivers ahead of me rapidly disassembled theirs as well.
(The power running boards are an option; maybe skip them if you need the most clearance possible)
Shad and the other Chevy folks told us to try Hill Descent Control in combination with low range and first gear. Even set to 1 mph, I wasn’t a fan. But I’m not a huge fan of these systems in most trucks as it is. I’d rather handle the brakes myself as I pick my line, slowly walking the truck down myself. “This is like a lot of men, I just don’t trust it” I told Shad about six feet down the hill as I poked at the button and disabled the system.
Between the front-facing camera and a careful line, I negotiated the downhill without damaging anything or otherwise feeling nervous. The Silverado 2500 took much more brake pedal input to maintain such a slow speed, but it weighs an entire Acura Integra more than the Colorado so… not a big deal.
In a similar vein to Ford’s F-250 Tremor, the Chevy Silverado 2500 ZR2 and ZR2 Bison are meant to be the ultimate off-road toy themselves, instead hauling your more-ultimate toys out to the middle of somewhere. You can go farther than in a more stock truck, but you probably won’t go quite as crazy as we did in the Colorado. Or even as we did in these red and gray 2500s. But it’s pretty neat to know that you could.
Are ZR2 and ZR2 Bison Worth It?
Off-roading successfully follows a pretty simple formula, one that Chevy has embraced here with both trucks I drove. In both cases, choosing the ZR2 trim level is an easy way to get some proper upgrades backed by a factory warranty. Those upgrades over a street-focused truck will get you pretty far off the beaten path and, to me, seem worth it if you’ll be spending your weekends as far from pavement as you can get.
I’m less sure on the Bison package, at least for the 2500 HD. On the biggest ZR2, choosing the Bison package adds $9,135 to the truck’s sticker. It’s a shorter list of upgrades compared to the Colorado ZR2 Bison and they’re not quite as function-first as on the bébe truck.
Pricing hasn’t been released yet for the Colorado ZR2 Bison, but I’d be more inclined to add the package given the hardware upgrades. The jounce control dampers alone are worth it, alongside the bigger wheels and tires that you’d probably install anyway.
I’m no seasoned off-roader, and my ability to critically evaluate some of the nuance in these trucks is not gonna be there compared to some others who also drove them. Conversely, I hopped in two trucks and took them through some relatively tough trails with minimal experience and plenty of confidence.
Oh, and given we were in the desert, only one letter off from dessert… I just had to get a few others to join me in making some donuts. As with everything else we’d done that day, the ZR2s made it easy.
That mix of capable-yet-approachable may be the ZR2 and ZR2 Bison’s best selling point.