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Cooper Discoverer AT3 XLT Tire Review

A Legend Reborn

Oct 9, 2018
Photographers: Jason Gonderman
Though it may come as a surprise to some, Cooper’s Discoverer line of off-road tires dates back more than four decades. Seeing as there’s no shame in improving on a good thing, Cooper launched not just one but three new tires under the Discoverer AT3 name. All similar in basic design, the AT3 4S is the base of the line and comes with a 65,000-mile warranty, available in 37 sizes. Adding additional features aimed at the crowd that tows and hauls frequently is the AT3 LT, which has a 60,000-mile warranty and is available in 21 sizes. The tire that most intrigued us is the pinnacle AT3 XLT, which is the most extreme of the bunch. While designed for hard-core use, the XLT still comes with a 60,000-mile treadwear warranty and is available in 29 sizes.
Photo 2/8   |   Cooper Discoverer AT3 XLT
For the purpose of our testing, we ordered a set of Discoverer AT3 XLTs in 35x12.5R18, mounted them to a set of 18x9-inch Dick Cepek Matrix wheels, and bolted the whole setup to our trusty Ford F-150. Coming off a different set of all-terrain tires, we immediately noticed how quiet and smooth the AT3 XLT was. So quiet, in fact, that we could hear new squeaks and rattles that we never knew the truck was making. Cooper has created what it calls Whisper Grooves, which reside on the inner edge of the outer tread blocks (in a sawtooth pattern) and provide a barrier that reduces road noise. Also with a cute new name is the company’s Even Wear Arc Technology. Simply put, the tire’s shape has been engineered to balance pressure at the tire-to-road contact patch. What this equates to is more even on-road tire wear and better handling.
While the AT3 XLT is an extremely competent road tire, even stopping an average of 10 feet shorter than the competition in Cooper’s testing, off-road is where it is meant to shine. Its tread, with Durable Tread Technology (we really can’t make these up), features stone ejector ledges, which help the tread to quickly dislodge stones and gravel. Ejecting stones—or preventing them from sticking in the first place—helps to prevent drilling into the tread. Clear tread also provides for better traction on- and off-road. Side lugs are staggered into what Cooper calls Traction Shoulders. These provide extra gripping surface while also providing additional traction in mud.
Photo 3/8   |   Cooper Discoverer AT3 XLT Tread
The AT3 XLT is also more visually appealing than the 4S or LT, with larger sidewall designs that are also functional, providing added protection and increased strength. Out in the wild, all of these features come together to create a tire that is impressively capable when the pavement gives way to dust. Graded roads, rocky trails, and wet washes are tamed with ease. Soupy mud and large slick boulders will take some finesse to get through, but that is true of most all-terrains tires.
While there will always be trade-offs between on- and off-road performance, the AT3 XLT manages them well. While it may not be the best choice for your dedicated mud buggy or rock racer, these new Discoverers from Cooper are great for the truck or Jeep that is driven to work during the week and hits the trails with any frequency on the weekends.


Tire: Cooper Discoverer AT3 XLT
Sizes Tested: 35/12.5R18
Type: Radial
Load Range: E
Maximum Load: 3,415 pounds at 65 psi
Sidewall Plies: 2-ply polyester
Section Width: 12.5 inches
Overall Diameter: 34.96 inches
Tread Depth: 16.5/32
Weight: 66 pounds
Test Vehicle: Ford F-150


Dick Cepek Tires & Wheels
Stow, OH 44224
Cooper Tire
Findlay, OH 45840