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Cooper Discoverer S/T Tire Review

Mud tire? All Terrain?

Pete TrasborgPhotographer, Writer

Cooper likes to call these tires an all-terrain. We can see that. They don’t really have the huge voids of a mud-terrain. But calling these tires an “all-terrain” is sort of like saying Kate Upton is a “girl.” The term really doesn’t do justice to what we are talking about.

These aren’t Cooper’s flagship tire, but we think they very well could be. They might be the most aggressive “all-terrain” we’ve ever tested. They have a great combination of tightly spaced lugs and large void areas that make them work well over a wide variety of terrain. We were looking for a tire that performed off-road but got us better performance on the street for our daily commuting. We bolted these to both our ’01 TJ and our ’98 Cherokee, and they worked great on both.

As we already said, they aren’t quite a mud-terrain. However, they do sort of sound like a mud-terrain tire. We attribute that to the wide void area. We say “sort of,” because while even the deaf Trasborg could hear them on the road, they were by no means annoying on either of the vehicles we’ve tested them on. The hum from the tires is more than many other all-terrains but still doesn’t come close to the loud growl of a mud-terrain tire. We broke them in for about 5,000 miles before we took them off-road. In the 10,000 miles as of this writing, they are wearing really well. If we don’t chunk it really bad and rotate the tires regularly, 50,000 miles might be a possibility.

In the sand, the tires do well. They aren’t so gnarly that they dig down immediately to China, so they are forgiving of clutch-dumping antics. However, even though they seem more aggressive than most other all-terrains, they weren’t able to get us as far up the dune as a more aggressive mud-terrain. So long as we weren’t trying to climb dunes, it’s a really easy tire to live with in the sand. For smaller dunes, like out at Silver Lake, Michigan, they’d probably work great. We are talking dunes like Comp Hill in Glamis, California, where they might not be the best choice.

While we never got to get these things into super-deep snow, we had ’em in about 12 inches of snow and they did well, even with our XJ. We had it fully loaded up for a camping trip, and it still clawed. We had to put the rear locker in for one patch of ice, but if we had the studs in the tires, the Jeep would have climbed right up.

We got it into deep slop in the TJ, and predictably, we had to use the winch—that’s what happens when you bury your Jeep to the axles. With the XJ, on a shallow mud field, we were able to see that the tires cleared out OK. The larger grooves cleaned out very well with minimal throttle, but the tighter-packed stuff took more. In Georgia clay, for example, you might have problems clearing them out. Again, while they are an aggressive all-terrain, they are still an all-terrain.

In the rocks, we fixed the lockers in the XJ and tried the lockers out on sandstone, some loose shale, and some loose hillclimbs. We didn’t take any chunks out of the tires, and they hooked up, especially on the sandstone. On the loose stuff, we had to spin ’em, but we didn’t hurt them. However, for mud-covered stuff, we had problems hooking up. The rubber compound hooks really well when dry, but we had to warm it up a bit to get it to grab on mud-covered rocks.

On-road, we’ve got no complaints so far. The tires do great in the rain and snow. Our XJ has a slight problem with the ass-end coming around if we really stand on the brakes. That doesn’t reflect on the tires, that’s a swapped-in-axle issue. But the point is, we got used to the rear end coming around on us really fast in the rain with our old tires. With these, it was less likely to come around, and we were pleasantly surprised to learn that all our hard-acquired anti-skid skills weren’t really needed so much anymore. While they do pull if you run them through a deep puddle, it’s totally manageable. We attribute that to the deep center groove and deep grooves from that to the edge of the tire.

Overall, this would be a great tire for a Jeep driven on-road during the week while not having to worry about destroying the tires with light weekend wheeling or expeditioning. If you were a hardcore rock hound or want to primarily run rocks or mud, this might not be your tire. Unless the rocks were slickrock or sandstone, that is.

Tire Specifications
Make/Model: Cooper Discoverer S/T
Country of Origin: USA
Size Tested: 35x12.50R15
Type: Radial
Load-range: C
Max Load (lbs): 2,535
Sidewall Construction: 3-ply polyester
Tread Construction: 3-ply polyester and 2-ply steel
Approved Rim Width (in): 8.5-11
Tread Depth (in): 0.787
Tread Width (in): 10.2
Section Width (in): 12.9
Overall Diameter (in): 34.88
Weight (lbs): 69

More and More Tires
Here at Jp, we have been putting tires to the test for years now. If you have a question about a certain tire, we may have already answered it in our huge online tire review known as “The Burning Ring of Tire.” If the tire you want to see is not on The Ring, keep your eyes peeled—we are going to review a new tire in every upcoming issue of Jp magazine.