Cooper Discoverer Radial STT Tire Review & Rating

The Discoverer Radial STT from Cooper is designed to provide some of the best off-road traction possible. Built for use on pickups, SUV’s and other off-road vehicles, the STT also offers surprisingly good performance on-road as well.

Cooper’s unique tread compound that is used on this model is designed to be more resistant to cuts, tears and chunking during extended off-road use. This compound is matched to a computer-optimized tread design that features a non-directional tread pattern. The tread extends down the sidewall which not only creates an aggressive and rugged looking tread design, but also adds more grip on the rocks and enhanced performance in soft terrains.

Cooper Discoverer Radial STT Tire Review

Scalloped shoulder tread lugs provide enhanced traction on all types of terrain. This is a tire that also has good grip in deep water and in the snow, something you might not expect from a tire like this. In addition, on-road drivablity is very good.

The tire comes with a tapered stone ejector rib that works to keep rocks and stones from getting caught in the tread. These ejectors also increase grip on soft terrain. An added rim protector that does a good job at preventing debris from damaging your wheels.

Inside the tire you will find Cooper’s Armor-Tek3 Carcass Construction that consists of two radial polyester body plies and one angled ply that combine to form a full 3-ply construction for increased impact resistance. Another benefit to this tougher tread makeup is that it extends treadlife. We’ve heard drivers mentioning in reviews that tread life is much better than most in this class, with some getting 60,000 miles out of the tire.


  • Off-road traction and performance is among the best you’ll find   
  • On-road drivability is very good for an MT tire   
  • Excellent tread life   


  • Tires get a little more noise as they wear down   

Overall Thoughts

Rarely will you find a tire like the Cooper STT for off-road applications. It’s one of only a few different models on the market today that provides the kind of outstanding all-around performance that puts it at a higher level than the rest. No hype intended with this statement…it is that good of a tire.

Off-road, the STT goes through anything and everything. Rock, sand, dirt, mud, gravel, snow and more is not a problem for this tire. Add in the more than capable on-road drivability and you have the type of tire most every driver looks for. Review after review from other owners of the STT confirms exactly what we found; this tire rocks.

Overall, we rank the STT as one of the better models in this class. Yes, you can’t go wrong with the BFGoodrich KM2 or Fierce Attitude MT, but we rate the off-road performance just a bit higher on this model. Cooper has put out an exceptional tire in the STT.

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What Vehicles Will The Cooper STT Fit?

(This is not a complete list of ALL vehicles this tire will fit)

  • Chevrolet Silverado, C2500, Blazer, Tahoe, Traverse   
  • Dodge Ram, Nitro, Durango   
  • Ford E-250 Econoline Van, F-150, Excursion, F-250   
  • GMC Sierra, Yukon, Jimmy, Savana   
  • Honda Passport   
  • Hummer H3   
  • Isuzu Rodeo   
  • Jeep Liberty, Grand Cherokee, Wrangler   
  • Land Rover Defender   
  • Nissan NV2500, Xterra, Pathfinder, Frontier   
  • Suzuki Equator   
  • Toyota FJ Crusier   

Tire Sizes


31-1050R15LT 109Q C OWL
32-1150R15LT 113Q C OWL
33-1250R15LT 108Q C OWL
30-950R15LT 104Q C OWL
35-1250R15LT 113Q C OWL


LT225/75R16 115Q E OWL
LT235/85R16 120Q E BL
LT245/75R16 120Q E BLK
LT255/70R16 108Q C OWL
LT265/75R16 123Q E OWL
LT285/75R16 126Q E OWL
LT305/70R16 124Q E OWL
LT315/75R16 127Q E OWL


LT245/70R17 119Q E BLK
LT265/70R17 121Q E OWL
LT285/70R17 121Q E OWL
LT295/70R17 121Q E BLK
33-1250R17LT 114Q D OWL
35-1250R17LT 121Q E OWL
37-1250R17LT 124P D BLK


LT275/65R18 123Q E OWL
LT275/70R18 125Q E BLK
LT305/60R18 121Q E BLK
LT325/60R18 124N E BLK
LT325/65R18 127N E BLK
35-1250R18LT 123Q E OWL


33-1250R20LT 114Q E BLK
35-1250R20LT 121Q E BLK

Price Range

Cooper Discoverer Radial STT prices range from approximately $154 and up. You may also find occasional rebates, discount prices, coupons and special offers on this tire.

Click Here To Find The Lowest Prices On All Cooper Discoverer Radial STT Sizes


Cooper provides a limited warranty on the Discoverer STT. Tire uniformity is guaranteed for the first 2/32 inch of wear. Materials and workmanship are covered for 5 years and include free tire replacement during the first 2/32 inch of wear. Cooper then prorates out the amount for the remaining time period or down to the final 2/32 inch of wear.

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