Cooper Discoverer AT3 XLT Tire Review

Going back to the drawing board isn’t always a bad thing. Taking what worked the first time and improving upon it is what makes products reach their full potential. When it comes to off-road tires, manufacturers are no strangers to giving sequels to their flagships. Now, we have Cooper and its Discoverer AT3 XLT, a development of its successful all-terrain Discoverer AT3.

Up until recently, the AT3 XLT was a hush-hush project that Cooper didn’t want teased or spoiled ahead of its release. Keeping those rubber cards close to the chest, Cooper waited until it was shipping to stores to give us the chance to review the AT3 successor. Needless to say, we were excited!

The 37-inch Cooper Discoverer AT3 XLTs were a perfect match with the 17-inch Dirty Life Roadkill 9302 beadlock wheels. This was a serious upgrade compared with the stock wheels and tires.

And what’s more fun than getting to test out a set of one’s choosing? For us, nothing but the 37×12.50R17s would do. We teamed up with our friends at MaxTrac to go all-the-way “new” with this test, as they provided us with a barely-broken-in 2018 Wrangler JLU to do the honors.

Background Of The Tire

To get a better understanding of the AT3 XLTs, we spoke with Cooper’s Director of Brand Management, Jessica Egerton. As it turns out, Cooper’s Discoverer line dates back more than 40 years, and represents Cooper’s focus on delivering tires that offer all-terrain traction and true durability.

“When we upgraded the Discoverer AT3 XLT tires, we kept the biggest musts of the consumer in mind,” said Egerton. “That’s why the tires hold up on rough roads, are constructed to provide a stable ride when hauling and yet are adaptable enough to provide a quiet, comfortable ride on the highway.”

Cooper gave the AT3 XLT a rigorous round of testing before it went into full-scale production. "These tires were driven over 8,000 miles on sharp gravel in a controlled test, to ensure they would meet our exacting standards for durability," commented Egerton. During these tests, the tire was noted to stop on average at least 10 feet shorter on wet roads when compared with competing LT all-terrain tires.

There are several standout features of the AT3 XLT, which Egerton was able to spell out. One of these was Even Wear Arc technology. “The tire shape is designed to balance pressure across the tire-to-road contact area,” she said. “It promotes even tread wear and superior handling on the highway.”

Another feature was Durable Tread Technology, which “provides all-season traction and durability for hauling, as well as helps the tire withstand assaults from dirt and gravel,” said Egerton. Yet the AT3 XLT packs another punch, one that is new and exclusive to the tire – Rugged Traction Shoulders. “These are large, interlocking biting edges built into the sidewall to ensure traction and grip when traversing through mud, loose soil or across rocky surfaces,” said Egerton. “They also provide resistance to abrasions and punctures.”

The ridged sides of the tread blocks are called Whisper Grooves. According to Cooper, they act as a sound barrier, reducing road noise on the highway.

But we had to know – what separates or distinguishes the AT3 XLT from the regular AT3? Egerton said, “The Discoverer AT3 is well-known for its long-lasting tread wear and dirt road performance, while the Discoverer AT3 XLT tire features Durable-Tread Technology, enhancing durability, and enabling a best-in-class mileage warranty.”

Pairing with these puppies was a set of Dirty Life Roadkill 9302 beadlock wheels, which would be a great complement to the rugged AT3 XLTs. To confirm this, we spoke with Joe Podlovits of The Wheel Group.

By pure happenstance, MaxTrac had ordered a set of Dirty Life beadlock wheels to go with the Cooper AT3 XLTs. These wheels had the goods to really take abuse off-road and keep on going.

“Beadlocks are typically used in extreme off-roading situations,” he said. “They allow the tire to run at very low air pressure while keeping it firmly in place. The low tire pressure allows the tire to conform to harsh terrain, like rocks, and achieve maximum traction.”

Another great feature of the wheels was the 6061 forged aluminum beadlock ring. “The ring has a straight cut groove design, which secures the tire and keeps it perfectly in place,” said Podlovits.

The beadlock wheels use yellow zinc grade 8 bolts and washers, offering remarkable strength in even the most arduous conditions.

“We also gave the wheel a double helix pattern on the rim flange, increasing the grip on the tire bead,” he continued. “We even gave the wheel a second set of holes to mount the ring to, doubling its lifespan.”

On-Road Performance

Setting off from the MaxTrac shop in Anaheim, California, we had a trail in mind that would take about 45 minutes to an hour to get to. This would give us plenty of time to get familiar with the AT3 XLT’s road manners and how it dealt with turns, stops, and highway driving.

The tires were inflated to 30 psi and we took off. Along the way, we were expecting the tires to become noisier than cats in a burlap bag. However, for their size and width, these tires made a surprisingly low amount of noise. This was probably thanks to Cooper’s Whisper Groove technology, which mitigates road noise.

Driving around town, the AT3 XLTs made less road noise than we expected. They struck a great balance between being capable off-road and docile on-road.

Coming to stops, the tires had no trouble. We also did a few hard turns and found the AT3 XLTs to perform admirably, keeping us in control before we straightened out. All in all, the all-terrains showed they had the on-road manners that the average Joe or Jane would look for in a tire.

For the rest of the drive, the AT3 XLTs showed no negative signs. We pulled up to the trail we had selected and set out to see what the tires would do when the going got rough.

Off-Road Performance

We now entered the trail head and made our way to parts unknown. In the middle of a Southern California summer, terrain types like mud and snow are nigh impossible to find and drive on. Dirt, rocks, and sand are the bread and butter out here, and they were more than enough to put the AT3 XLT through its paces.

Paved road gave way to unpaved road, and off to our left was the first obstacle course to check out. Slopes and deep divots were on the menu, and the Jeep was hungry. We wouldn’t need four-wheel-drive just yet, but it was a good opportunity nonetheless to see how the tires would perform.

To Jeep's credit, the JL had a great amount of flex that it could call upon when going over uneven terrain, even with 37-inch tires! Only on very rough dips and crests did we hear rubbing from the tires.

It was altogether not a hard trial, and the Jeep was able to traverse the course with ease. It gripped on rocks at 30 psi and propelled the Jeep over, which would come in handy if this Wrangler ever went rockcrawling.

We came upon a side trail that had long sections with some twists and turns along the way. After driving down it for some time, we found it to be a good spot to test speed handling of the AT3 XLTs. It wouldn’t be prerunning at 90mph, but it would show us how well the tires could scoot while throwing turns into the mix.

In spite of speed and turns, the AT3 XLTs performed admirably. Grip was strong and steering correction was minimal during this portion of the test.

In two-wheel-drive, the Jeep was driven along the path at a brisk pace. What could have caused the rear to get squirrelly, instead did very little. The tires maintained grip throughout the side trail and required very little over-correction from the driver.

Our final area to test on was a rock patch near the trail. Flat and nary a slope in sight, we did what we could with what we had. The tires did a decent job here, with only a few slips off of smaller stones as we bumped and bounced over the stones.

On the rock patch, the AT3 XLTs gripped almost every stone with ease. Meanwhile, the stone ejectors fulfilled their purpose well, keeping the tread practically devoid of traction-robbing pebbles and rocks.

What was neat to see afterwards was how free and clear the tires were of rocks. This had to be the work of the built-in stone ejectors, which Cooper had the foresight to place in between the tread blocks. This could be seen at any time we stepped out to observe the Jeep in action, and it no doubt played a part in the AT3 XLT’s great traction. Having rocks clog up a tire can affect not only its grip but also its lifespan, so keeping them out of the tread is always a big plus.

Conclusion

All-terrain tires are those tires that appeal to drivers looking for the balance of off-road strength with on-road finesse and comfort. We’re excited to say that the Cooper Discoverer AT3 XLT fulfilled this mission, and then some.

When it came to street and highway driving, the AT3 XLTs rode well and took it easy on our ears. We could hold a conversation inside the cabin and not have to shout over gaps of air trying to squeeze out, like we would have on a knobby mud-terrain.

And off-road, the AT3 XLT delivered on its pedigree. It got us through dirt, gravel, inclines, and rocks with minimal slipping or sliding. With less tire pressure, it would have performed even better, and the beautiful Dirty Life beadlocks would have kept them locked and loaded for action – but we had to drive home on these puppies.

In conclusion, we heartily recommend the Cooper Discoverer AT3 XLT as an all-terrain option. You can find these tires in stores now, with 29 different sizes to fit 15-inch all the way to 20-inch wheels. Be sure to check out more from Cooper by visiting its website and Facebook page, and don’t forget Dirty Life wheels!

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About the author

David Chick

David Chick comes to us ready for adventure. With passions that span clean and fast Corvettes all the way to down and dirty off-road vehicles (just ask him about his dream Jurassic Park Explorer), David's eclectic tastes lend well to his multiple automotive writing passions.
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