Pirelli Scorpion All Terrain Plus vs Cooper Discoverer AT3 XLT

Here the Pirelli Scorpion All Terrain Plus and the Cooper Discoverer AT3 are very well made all-terrain tires being in the less aggressive category, so their on road usage is mostly preferred and that’s where they impress the most, but I am also going to closely discuss their off-road performance as well. Let’s begin.

Being a tire engineer, my deep research tells me that the Cooper Discoverer AT3 offers a softer compound (though it’s company denied to public it’s exact composition), which offers better wet traction in comparison. It also offers superior grip on snow as well, for the very same reason. Though it lacks slightly more off road as Pirelli Scorpion AT Plus grips in all directional and slightly wider grooves especially on sides which allows better self cleaning as well besides biting in to the ground.

Tread Structure

Both A/T tires offer a very different looking structure, where the Pirelli Scorpion AT Plus follows the new generation design with 2 outer longitudinal grooves containing central lugs in an interlocking arrangement.

Let’s start of with this tire first.

So, here we have S and P shaped lugs, initials of it’s name (no, it’s not a coincidence, though P looks more like a J).

Nonetheless, they are not for looks.

The S Shaped lug is bigger and provides the central most rib for on road stability (when you move directionally), and aiding to that are it’s reinforced foundations, that’s why the notches it makes are not full depth.

But these lugs still give enough biter with their off set sides.

And same goes for the surrounding lugs, carrying similar features, they have notches facing shoulders and similar rectilinear siping.

The shoulder lugs of the tire are smaller but have wide enough grooves between them there as well.

They make notches towards inner sides, and are staggered on the outer edges.

Though not visible, they also make slanted U shaped lugs on sidewalls which supply great off road bite as well.

On the other side, the Cooper Discoverer AT3 XLT offers a cleaner design.

This tire offers a 5 rib design having 4 conventional circumferential channels, containing blocks in pairs.

The middle most rib has slightly wider lugs which promotes on road stability, these lugs have full depth interlocking sipes and sharp chamfered edges.

The surrounding blocks have similar features and along with that their sides have snow vices in them (sharp saw toothed edges).

See if you can find them in the image above, they are also seen on the shoulder lugs.

The shoulder blocks offer similar tread features, including snow vices, and they also have ridges in between which connect all lugs together.

The XLT variant of the Cooper AT3 also offer thick sidewall lugs, which are just as aggressive as the Pirelli Scorpion.

Sizes Available

The Pirelli Scorpion AT Plus has limited 22 sizes (16 to 20 inches). They cone with following specs.

• Load ratings available: SL, XL, C, D and E
• Weight range: 29 to 60 lbs
• Speed ratings available: R, S, T, and H
• 13/32″ to 15.5/32″ of tread depth is seen.
• And all sizes have 50k miles warranty.

Moving towards the Cooper Discoverer AT3 XLT, here you see 32 total sizes with rim diameters 15 to 20 inches, with following specs.

• Speed ratings available: either R or S.
• Load range: C to F.
• Weight range: 44 lbs to 70 lbs.
• Tread depth: 16.5 or 17/32″ in all sizes.
• All sizes have 60k miles warranty.

Sidewalls

Off road tires are built strong and here their inner construction matters the most, to be even more specific, their sidewalls’ internal built is the main thing to consider.

Here both tire 2 ply sidewalls, with both of them having 2 ply polyester casing construction and 2 wide steel belts running on top.

Though in terms of durability, the Pirelli Scorpion offers one more layer of cap ply in comparison, though it remains lighter in weight.

Dry Performance

Traction of the tire has two parts, grip and cornering. Lets talk both.

Longitudinal Grip

How much directional grip a tire makes depends on the middle part of it’s tread. Middle area of the tread actually makes the most contact with the road as whole tire’s weight is emphasized over there.

Cooper Discoverer AT3 although offer better directional stability, it’s groove are wider in XLT variant. Other variants like the 4S and LT, are better though.

Pirelli Scorpion All Terrain Plus on the other hand, offers better contact with the road which results in superior grip. That’s why the tire has speed ratings going up to H.

Lateral Traction

The lateral traction of the tire comes from sides, as they play a significant role when a tire turns.

Basically when you curve a tire, all of the weight of the vehicle shift towards the sides of the tires, so the shoulder lugs and sidewalls make the most contact with the surface.

Here, the Cooper AT3 offers a slightly better traction, though the margin is very small, if not similar.

Steering Sensitivity

The more the tire weighs the lesser the steering sensitivity. Though there are other factors as well, for these tires this is enough for understanding.

Cooper Discoverer AT3 although offers stable lugs with foundational supporting ridges, Pirelli Scorpion All Terrain Plus offers a lighter overall structure, and with extra cap ply, the tire offers a better over and under-steering balance.

It’s handling stability is very sporty.

Wet Traction

The grip and handling on wet asphalts, is noted by considering the tire’s ability to remove the water. The better the water gets removed, the better the grip and hydroplaning resistance, let’s discuss these two separately.

Wet Grip

The overall wet gripping values depend on the tire’s siping number and design.

Cooper Discoverer AT3 although offers similar number of sipes, it’s design is much more better, comparatively.

It’s sipes basically have an interlocking design, all the way, so they don’t get stiff during handling and stopping to a halt. Moreover, the overall tread of this tire is also much softer, so the sipes get to have better efficacy.

Pirelli Scorpion All Terrain Plus on the other hand, does better with hydroplaning.

Hydroplaning

Water basically is not compressible, so it needs to get out fast, otherwise the tire can float on it. And this clearing of water tells how much a tire can grip and how well it is at hydroplaning.

The Pirelli Scorpion AT+ has open shoulder lugs in comparison, and this interconnects with the web of grooves in middle offering multiple channels to water to escape out easily.

Cooper AT3 has 4 circumferential channels which although offer good water removal, the limited sideways gap still don’t allow it to have as much hydroplaning resistance in comparison.

Fuel Economy

Fuel is largely dependent upon the overall rolling resistance of the tire, which then indirectly depends on how much the tire weighs and it’s tread composition.

With more weight the tire puts more pressure, and with tread composition, we get to know how much of that weight is put upon how much tread area.

Tread composition also tells us about the stickiness of the tire, some have high silica density and they simply don’t want to leave off too easy, enhancing the tire’s overall rolling resistance.

Cooper Discoverer AT3 has high silica in it’s compound, so where it weighs more, it sticks more as well, so it’s evident that it’s fuel economy is compromised.

Pirelli Scorpion A/T Plus is much better here, in fact its one of the best in this area, compared to other top A/T tires (my list).

Mileage

Tread wear is analyzed by looking at the tire’s composition and structure, and of course, it depends on rolling resistance as well.

Cooper Discoverer AT3 with softer composition is although more prone to wear, it’s tread depth still make things better. Moreover, its on road oriented design with longitudinal grooves also makes it last longer in comparison.

Pirelli Scorpion on the other side, wear off faster with it’s multiple biters and interconnected grooves, combined with smaller tread depth. That’s why this tire offers 10k less overall mileage warranty in comparison.

Comfort

Comfort depends on a lot of things, and noise is a main one here. Noise is generated when air hits the grooves, and that air mostly comes form shoulder lugs.

That’s why Cooper introduced Whisper Groove Technology, which basically reduces the flow of air form the shoulder gaps with the help of ridges placement (between the lugs).

Moreover, the tire is also better at absorbing the bumps of the road with it’s soaking rubber (which also has more tread depth, or should I say rubber thickness in comparison).

Pirelli Scorpion All Terrain Plus on the other hand has open shoulders and although it has pitch sequencing tread, it’s still louder comparatively.

Further more, it’s 2 cap ply on top and a thinner rubber (which is also more rigid) don’t cushion the vibrations of the road as good as Cooper AT3.

Snow Performance

Although both tires are 3 Peak Mountain Snowflake rated, the Cooper Discoverer AT3 is a better pick for on road snow.

The tire offers snow vices in outer longitudinal grooves which grab the snowflakes in them and provide superior contact with the snow. And its softer rubber is less prone to getting frozen up (which creates stiffness).

Pirelli Scorpion All Terrain Plus does better on slightly deeper snow, where it’s groove cones come in to action and they hang on to the snow there nicely.

Off Road Traction

Although there are various terrains to consider in this section, for these tires, I think the following ones is all you need to know about.

Mud

Mud has a thick composition and it can only leave out from the tire if it’s highly voided. That’s mud terrain tires do so good which provide balder design, so mud have a decent real estate over there to leave out.

Cooper Discoverer AT3 like I showed you in the design section above has no proper lateral channels (which is highly needed for mud removal), so it tends to get packed faster in comparison.

Though its staggered shoulders and sidewall lugs scoop the mud out of it’s way, and try to provide as much traction there as possible.

Pirelli Scorpion All Terrain Plus on the other hand, does better with evacuation as it’s shoulder lugs are more open, though it’s shoulders are not that impressive here.

Rocks

On rocks, you pressure down the air of the tire for maximum traction, and with this the sidewall shoulder help a lot. Now looking at the two, it can be seen how both tires offer similar traction form sides.

But considering the bigger scoops on shoulders of Cooper Discoverer AT3, its understandable why it offer better lateral traction in comparison.

Pirelli Scorpion AT+ on the other side, provides better climbing grip (but only directionally).

Sand

On sand, the tire is good with lighter terrains, as it focuses on forward momentum instead of digging with it’s smooth lugs.

Here both tires perform pretty well, but differently.

Cooper Discoverer AT3 is softer so it does better by providing better footprint with lowered pressure, but with sharper edges, it gets hard to maneuver this tire, climbing slopes.

Pirelli Scorpion AT on the flip side, is lighter and is smoother on sides, so its focuses on moving forward instead of digging, providing better incline traction.

Dirt and Gravel

On gravely roads, you need powerful stone ejectors that wont allow sharp stones and dirt to get lodged in.

Basically self cleaning of tread is all you need otherwise these trapped particles can damage the tread and loose traction of the tire, even though almost all off road tires are built with cut resistant rubbers.

Both tire although offers some kind of ejectors where Cooper AT3 gives you stone ledges, and Pirelli provides groove cones, the Scorpion AT is still more prone to stones getting stuck in its grooves.

Take Home Points

Cooper Discoverer AT3 and Pirelli Scorpion All Terrain Plus are both all-terrain tires where they focus on highway performance more.

Yet still the Pirelli does better on dry roads, whereas Cooper is great on wet with better siping, which by the way also yields superior traction on snow.

Off road both tires have mixed performance and it’s complicated to sum it up here.