Cooper Discoverer AT3 4S Review: Excellent Performance on All-Terrain

Off-road tires are often one of the most complex ones when it comes to their development. A company needs to make a tire with off-road capabilities but still perform well on the road. It means that the tire needs to be perfectly balanced to provide the best all-round performance.

In some cases, we may see a shift in the balance towards one side, which results in a tire better for the road, but worse for off-road or vice versa.

There are plenty of manufacturers that sell off-road tires, and among the more popular choices is Cooper. As part of their AT3 lineup, they released the 4S, and they have some bold claims about it.

To verify if the AT3 4S is just as good as Cooper claims, I put them to the test. They went through every conceivable test I could think of in multiple conditions and sum it all up in this review.

What are the features of the Cooper Discoverer AT3 4S?

Cooper’s claims about the AT3 4S are quite bold. They say that their tire has excellent performance on any terrain or any surface. The tires are designed with Adaptive-Traction Technology, providing the mentioned properties.

The company says that the AT3 4S will provide comfort while driving on the road combined with decent off-road capabilities. In addition to that, the tires should perform superbly in wet conditions.

What are the maintenance indicators?

Tire treads are the grooves in the bottom part of the tire that gives its properties. Considering that we are talking about an off-road tire, having a good thread depth is crucial for good wet performance. Like most modern tires, the Cooper Discoverer AT3 4S has a way of identifying when it reaches the end of its life regarding thread-wear.

Within the threads, the tires have indicators that mark the minimum 2/32-inch thread depth. Once the thread reaches that point, the markers become flush with the thread, meaning that it’s time to replace them. Once you reach this point, you will lose most of the performance of the tires.

The good news is that these tires have a relatively long life. Cooper will sell you the AT3 4S with 65.000 miles of thread-wear protection.

How does it behave on a dry tarmac?

Before I dive into how the tire behaves on dry tarmac, I feel there are a few things to mention. When you are purchasing an off-road tire capable of doing reasonably well on tarmac, you have to make some sacrifices. The general rule is that when you have excellent road performance, you tend to lose on the off-road capabilities a bit.

Considering everything I just mentioned, Cooper’s Discoverer AT3 4S proved to be excellent on dry tarmac. Keep in mind that this is a tire designed for all terrains and conditions, so you cannot compare it to some performance models.

Despite that, during the testing, the AT3 4S managed to grip reasonably well in the corners. Even when pushed to the limits, the tires enabled the vehicle to change direction relatively sharp. Again, I should point out that this is not a high-performance tire, but it still managed to impress me.

When I pushed the car well beyond its limits, I felt the tires breaking traction. It’s a situation that a regular driver wouldn’t face, but still worth mentioning. On top of that, these are tires that you’d fit on a truck or an SUV, meaning that you won’t be taking it to the track any time soon.

Another thing worth mentioning is the sidewall flex. Being an off-road tire means that it has a high sidewall, and every time you corner a little too hard, you can feel the tires flexing. This is a common trade-off in tires designed to be “good” in multiple conditions.

Cornering is only a part of the driving experience, and it can be useless if you cannot stop the vehicle safely. This is another aspect of the AT3 4S that surprised me. The stopping distance was shorter than I expected, and even managed to trade blows with some regular road tires.

Overall, the dry performance of the tires impressed me. I may have low expectations considering that it’s an all-terrain tire, but I was pleased with how it handled on the dry tarmac at the end of the day.

How is it over wet and slippery roads?

Designing a tire capable of decent performance in multiple conditions means that it will need to do well in the rain. In this segment, the AT3 4S didn’t surprise me as much as in the dry. The tires are designed with Aqua Vac channels and sips on the thread blocks. So, what do these mean when driving them in wet and slippery conditions?

The performance of the AT3 4S turned out to be just as I suspected. The tires managed to grip to the road despite the non-ideal conditions. While the grip levels cannot be compared with the ones I witnessed in the dry, the still managed to stay glued to the road. They did break traction, but considering how much I pushed them, it’s not something that you should worry about.

Most of what the AT3 4S offered is something that I already expected. The tires provided predictable handling, meaning that I know exactly when they would break traction and correct it. The braking distance was again impressive, considering that I was testing them in wet and slippery conditions.

What did surprise me the most was how well it resisted hydroplaning. This is thanks to the Aqua Vac channels and sips, ensuring that the excess water is thrown out the sides. As it pushes the water to the sides, it ensures that the tire doesn’t lose contact with the surface.

With that being said, how is it on snowy roads?

For a tire to perform well on snow and ice, it needs to have a softer compound. In most cases, a tire that performs well in the summer will be terrible in the winter, and the same goes the other way around. On the other hand, the AT3 4S’ compound is enriched with silica, ensuring that it has similar summer and winter properties. It means that it can be soft enough to get the most out of it.

Most of what I mentioned in the previous section can be applied here. Tires with deeper grooves tend to better dig in the snow and provide a better driving experience, and that’s the story with the AT3 4S. When you get behind the wheel of even a powerful truck or an SUV with these tires, you will feel the confidence in the first 10 feet of driving. This should not surprise anyone, as they have the three-peak mountain snowflake rating.

Now I must mention a slight trade-off. While they have the three-peak mountain snowflake rating, they are not full snow tires. The AT3 4S will handle deeper snow, handle good and break decently, but they cannot be as good as snow tires. This is to be expected. Snow tires are developed to be best on the snow, while they are designed to work well in multiple conditions.

In general, considering the purpose, I would say that their snow and ice performance was not the best, but was more than enough for the average driver.

Is it suitable for off-road driving?

Cooper sells the AT3 4S as SUV and truck tires for on-road and off-road. When it comes to off-roading, there are some things you should be aware of. Tires designed for on and off-road usually balance their performance to ensure decent performance in both cases. These tires are no different.

They will fair well in off-road situations, as long as you don’t expect too much of them. You will get solid traction over hard and loose surfaces, but don’t expect to get to the top of the mountain with them. For that, you need full-fat off-road tires.

Is it comfortable and refined?

The one thing that most off-road tires suffer from is the noise, something which Cooper managed to fix. Yes, these are not dedicated off-road tires, but still, some of their competitors tend to be noisy. When driving the AT3 4S, I found that the noise level was decent even at highway speeds. They weren’t whisper-quiet, but nothing obnoxious.

On the comfort side of things, if I didn’t know what I was driving, I’d say it was a highway tire. It managed to deal with bumps on the road better than anticipated.

You can see more Cooper Discoverer AT3 4S Review here: Video created by Dacia Duster Trails

Should I buy the Cooper Discoverer AT3 4S?

The answer to this question will depend entirely on you.

Even though they are designed to work in multiple conditions, they still manage to do that very well. You should also be aware that you won’t get the best performance in certain situations. At the end of the day, it all boils down to your driving preferences and the climate. If you do some light off-roading and you drive your car in all four seasons around the year, the AT3 4S are excellent for you.