Cooper Discoverer AT3 4S 

Tires Tested

On the Road

The quality of the ride between both tires averaged out close enough that we can say most consumers won't notice a significant qualitative difference between the two. However, that does not mean the experiences were identical. The Discoverer AT3 4S was firm, with more undulation over smaller imperfections, and while larger impacts were somewhat controlled, the Discoverer Road+Trail AT was notably softer over those same big hits, despite being a bit bouncier. Both were largely comfortable, with minor, nuanced differences between the two. Their respective noise profiles were a bit more pronounced, and while some of these examples are less severe than their descriptions here, it's important to dive into the minutia separating the two. The Discoverer AT3 4S kept an overall low volume across most surfaces, with some standout moments. It exhibited a regular drone over concrete and continued when switching to asphalt with a pitch change, along with some cyclical rhythm above a lower-volume grind. Conversely, the Discoverer Road+Trail AT expressed a higher-pitched performance, which seemed to result in a greater variety of tones, giving a slight edge to its predecessor here. Finally, the response to steering input was a fairly clear subject of ongoing improvement: the Discoverer AT3 4S was decent, a bit sluggish in response, needing to be led a bit before the tire catches up. The Discoverer Road+Trail AT was much more alert by comparison. It felt appropriately weighted, linear, almost athletic, which is really saying something for this category.

On our Track

Around the wet track, both tires showcased solid traction for the category, with a small step up for the Discoverer Road+Trail AT, which naturally translated into similar braking characteristics also. When it came to steering the tires around the track, the Discoverer AT3 4S's tendency for slower steering affected its response time, and wouldn't respond as well to overlapping inputs or being hustled too hard. Too much speed and it would understeer through corners. It could rotate if coerced, but never happily. The Discoverer Road+Trail AT by contrast, was more eager and alert, and felt like the front axle was really leading the action. It would rotate around corners easily and it was forgiving, leaving room for later inputs, catching up to driver intention with ready excitement. Fairly normal for an All-Terrain tire: it was not particularly precise, but in the right conditions, satisfying to drive.

Once the track dried off, the Discoverer AT3 4S shook off the droplets, dusted off its shoulders and made a show of gliding effortlessly around the course. No wasted movement, admittedly very little rotation, just efficient, neutrally balanced professionalism. It wasn't playful or quick, particularly in the steering department, it was simply a polished, capable tire doing the job it was asked to do. On the other hand, the Discoverer Road+Trail AT was an improvement in steering, and its additional responsiveness translated to a much more eager, excitable experience. It would rotate around a corner, but not in a way that allowed it to translate the movement into speed. The tire allowed our drivers to pull showy maneuvers, but it didn't make them useful for fast laps. Slowing down and driving carefully may not have been as thrilling, but it actually resulted in faster laps.

Driving in Winter Conditions

Snow and ice are notoriously challenging weather events to deal with as drivers. While all-terrain tires are designed to adapt to a variety of conditions, that flexibility in design also means they're not fully equipped to match the purpose-built performance of a winter tire. It's not uncommon that the low-traction conditions created by snow and ice can significantly change, or even invert, the driving characteristics seen on dry or wet tracks. It's more impressive then, that both tires remained fairly consistent in their handling during snow avoidance maneuvers. The Discoverer AT3 4S retained the same kind of no-nonsense behavior it showed in the dry and wet, with little slip, little fuss, and steering that was responsive, but unhurried. The Discoverer Road+Trail AT adds urgency to the mix, creating more responsive turn-in and directional changes without losing a sense of feeling planted and stable despite the conditions. As with other surfaces, it could also be coaxed into a bit of rotation, but otherwise, remained well-behaved, doing exactly what was asked of it. The objective numbers bear this out as well, with both tires well-matched in straight-line traction, only a foot apart in acceleration, and the Discoverer Road+Trail AT gaining an additional 5 feet of stopping distance over its predecessor. Braking distances on the ice yielded a minor upset, with the Discoverer AT3 4S stopping just shy of 3 feet shorter, but outside of that narrow case, we saw the kind of distinct progressive improvement expected from a successor tire.

Conclusion

Our preview drive reminds us that indeed, everything changes. The Discoverer AT3 4S was a well-loved tire that performed well in its category, proving itself as one of the leading tires in its segment. Following up on a success like that is a difficult task and carries a lot of pressure to get it right. For the most part, the new Discoverer Road+Trail AT feels like a proper incremental refresh: improving the aesthetics of the tire, showing superior wet and winter performance, and at least matching the quality of its predecessor's on-road comfort. Cooper took the Discoverer AT3 4S, examined what worked, and what didn't, and made the kind of focused, gradual improvements where it was needed and mattered most.