The Discoverer AT34S is Cooper's On-Road All-Terrain tire designed for the drivers of pickup trucks, crossovers and full-size SUVs looking for a tire that blends the off-road grip they need with the on-road comfort they demand. Engineered to deliver traction on any surface it may encounter, the Discoverer AT34S combines on-road manners with off-road capability and provides confident light snow traction that meets the tire industry's severe snow service rating requirements and earns the three-peak mountain snowflake (3PMSF) symbol.
Utilizing Adaptive-Traction Technology, the Discoverer AT34S combines a silica-based tread compound into the Secure-Grip all-terrain pattern. The open, five-rib design is engineered to provide wet and dry performance, in addition to off-road capability. The circumferential, Aqua Vac Channels and wide, lateral notches help evacuate water from the contact patch and resist hydroplaning. Micro-Gauge ZigZag sipes create biting edges for added traction in slippery conditions while retaining tread block stability for dry traction and handling. Snow Groove Technology utilizes saw-tooth block edges in the outboard grooves to retain snow in the tread pattern for snow-on-snow traction.
The internal construction of the Discoverer AT34Sconsists of a durable, two-ply polyester casing. A single-ply, nylon reinforcement above two high-strength steel belts further increases durability and handling response, along with providing high-speed stability.
Note: While non-winter tires featuring the three-peak mountain snowflake (3PMSF) symbol may provide additional longitudinal snow traction beyond what all-season (M+S) tires not bearing the symbol can deliver, they do not match the capability of a true winter tire in all adverse weather conditions.
Related Information: What is the three-peak mountain snowflake symbol (3PMSF)?
October 10, 2023
"The only constant is change."
-Heraclitus, 6th Century B.C.
Progress is one of the enduring hallmarks of mankind - innovation, advancement, momentum. It is as inevitable as entropy, as gravity. However, simply because it's a guarantee doesn't minimize the value of examining each step along the way. Every time a new tire is brought to market, we have to ask ourselves: why? What's changed? What justifies this new version, this new variation?
In Cooper's case, the question is even more relevant, as the new Discoverer Road+Trail AT follows up the immensely popular Discoverer AT3 4S, a tire that has consistently ranked at-or-near the top of customer surveys since shortly after its debut. There's a great deal of research, testing, tuning and iterative manufacturing that goes into even a minor tire refresh, so even small upgrades are worthy of note.
The exterior differences are evident, a more rugged sidewall design that flows nicely from the shoulder lugs, a moderate, but more aggressive tread pattern, even the name is more evocative of its off-road DNA. At Tire Rack, we don't just settle for what we can observe on the surface, and our testing team is always looking for more questions to answer. So, we set our team to the roads and our own custom-built track, to find out what drivers can expect from both tires.
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.
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.
| Wet Track | Average Times | 50-0mph | ||
|---|---|---|---|---|
| Slalom | Total Lap | Lateral gs | ABS Stop | |
| Cooper Discoverer AT3 4S | 5.71 | 34.51 | 0.66 | 112.0 |
| Cooper Discoverer Road+Trail AT | ||||
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.
| Dry Track | Average Times | 50-0mph | ||
|---|---|---|---|---|
| Slalom | Total Lap | Lateral gs | ABS Stop | |
| Cooper Discoverer AT3 4S | 0.81 | |||
| Cooper Discoverer Road+Trail AT | 5.27 | 31.76 | 0.81 | 85.9 |
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.
| Actual Ratings/Test Values | ||
|---|---|---|
| Cooper Discoverer AT3 4S | Cooper Discoverer Road+Trail AT | |
| Snow Acceleration w/TCS (feet) | 19.10 | 18.00 |
| Snow Stopping Distance (feet) | 73.50 | 67.90 |
| Ice Stopping Distance (feet) | 50.2 | 53.1 |
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.
(929)Tire Category: On-Road All-Terrain
| Best in Category |
| Miles Reported |
| Recommended |
| Treadwear |
Cooper Discoverer AT3 4S
|
|---|
| 97% |
| 9.4M |
| 8.5 - Good |
| 8.6 - Excellent |
|
|
| 9.0 - Excellent |
|
|
| 9.2 - Excellent |
|
|
| 8.5 - Good |
|
|
| 8.8 - Excellent |
|
|
| 8.5 - Good |
Customers praise the Michelin Primacy MXM4 for its smooth and quiet ride, with comfort scores consistently in the 8-10 range. Treadwear receives strong marks for long-lasting durability, though a few reports of uneven wear appear in lower-mileage use. Winter traction earns positive feedback for confidence in light snow, though some note mixed results in icy conditions. Wet traction shines with 9-10 ratings for hydroplaning resistance and grip, while dry traction delivers responsive handling and stability. As a Grand Touring All-Season tire, it excels in comfort and year-round capability, with most drivers reporting satisfaction across daily driving scenarios.
AI-generated from the text of customer reviews
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The Cooper Discoverer AT3 4S was delevoped for drivers of pickup trucks, crossovers, and full-size SUVs, looking for a tire that blends off-road grip with on-road comfort.
The Cooper Discoverer AT3 4S is a long-standing consumer favorite, so we used it as the benchmark to test the newest, untested entries in the category.
Read the Full Test Report
In the real world, trucks, Jeeps and SUVs are primarily used to conquer the mundane tasks of everyday life, often never leaving paved surfaces. But confident off-road capability when it's needed and an aggressive look are still key.
Several new On-/Off-Road All-Terrain tires designed for the way drivers actually use them have a greater emphasis on noise, comfort and wet traction.
How did they perform in our testing?
View Road Manners & Dry/Wet Track Results Video
In the real world, trucks, Jeeps and SUVs are primarily used to conquer the mundane tasks of everyday life, often never leaving paved surfaces. But confident off-road capability when it's needed and an aggressive look are still key.
Several new On-Road All-Terrain tires designed for the way drivers actually use them have a greater emphasis on noise, comfort and wet traction. How did they perform in our testing?
View Snow Traction/Handling Results Video
Read the Full Test Report
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