Both the Nitto Terra Grappler G2 and the Cooper Discoverer AT3 are all-terrain tires, offering excellent performance and comfort for your SUV and light pick up trucks. Let’s check the unique features both provide.
As a tire engineer, from my perspective, the Nitto Terra Grappler G2 excels in dry traction and hydroplaning, as well as off-road performance on rocks and mud. On the other hand, the Cooper AT3 excels in wet road performance, snow traction, comfort, fuel efficiency, and tread wear. It is also comparably effective in rocky off-road terrain, where it excels on sand traction.
Table of Contents
Durability
To ensure strength and durability, the internal construction of an off-road tire must be carefully engineered, including the use of cut resistant rubber, deep voids in the tread, and a polyester casing for the sidewalls.
Both tires although offer deep enough tread and a chip resistant rubber, the Cooper AT3 is less durable still, with it’s only one cap ply of nylon.
While the rest stay the same (internally), compared to Nitto Terra Grappler as both tires have 2 ply polyester casing and 2 wide steel belts running on top.
Tire Sizes
Speaking of Nitto Terra Grappler first. This tire comes in 17 to 24 inches (rim sizes).
And they have speed ratings of R, S, T and H, and load ratings of SL, XL, D, E and F.
The tire is pretty heavy where it’s heaviest is 80 lbs, and lightest sizes is 30 pounds.
Tread depth also vary wildly on sizes as it goes from 12/32″ and reaches up to 17/32″.
Moving towards the Cooper Discoverer AT3 XLT, this tire comes with 32 sizes in total (15″ to 20″ rim sizes) and they have speed ratings available in either R or S, and load ratings of C to F.
Weight of the tire is lighter in comparison, and it ranges from 44 and goes up to 70 lbs.
Moreover, all sizes, have either 16.5/32″ or 17/32″ of tread depth (so greater on average).
Tread Design
The Cooper Discoverer AT3 offers a more optimized design for highways.
It although makes similar looking 5 rib design, it’s lugs are more packed together.
Moreover, on each rib, these lugs run in pairs, as they are joined together with each other with tie bars in between.
Also all blocks have interlocking full depth siping design, which is very efficient with snow and wet traction.
Moving towards shoulders, the lugs here are also no different, though they do have a few extra features.
Towards outer edges they make staggered shoulders and thick sidewall lugs, and towards inner, they have snow vices.
Moreover all these lugs are also connected with each other with ridges in between. Cooper calls it Whisper Groove Technology as it helps with noise.
Read full review of Cooper AT3 here.
Moving towards the Nitto Terra Grappler G2, this tire is also pretty on road aligned.
It features a variable pitch tread with chamfered edges and deep sipes on its three main ribs, providing excellent snow performance.
Though, its wet traction needs improvement, as these sipes are not optimized for that.
The middle most rib is thicker compared to outer two, so it makes more rubber to road contact providing directional traction.
Whereas the outer ribs have stone ejectors connected with shoulder lugs and this combined with notches form both side, these (outer) circumferential channels are made very efficient at self cleaning.
Moving towards shoulders, its tread makes staggered lugs all of them sit joined together by reinforced foundations underneath.
Read full review of this tire here.
Dry Traction
Dry traction has two parts, directional grip, and sideways grip. Let’s talk both.
Dry Grip
Directional grip, which refers to a tire’s braking and acceleration performance, is largely determined by tread’s footprint. So the larger the footprint, the better the directional grip.
And here the middle section is very crucial, as that part gets to meet with the surface with larger force.
Now, although Nitto Terra Grappler offers a fatter rib there, it’s lateral grooves splitting the blocks are wider, and with that, its not able to connect enough with the road comparatively.
Cooper Discoverer AT3 on the other hand, runs in pairs, and so although the lugs may seem divided, they are joined form underneath, and still the gaps are narrower.
So you get a better connection with the road with this tire, which results in superior grip.
Though you can make things even better, (considering dry grip), as for that you can get less aggressive variants like the Cooper AT3 4s or AT3 LT, instead of XLT.
Sideways Grip
Sideways grip, also known as lateral traction, is a measure of a tire’s ability to corner and is based on the performance of the tire’s sides.
And here the same story goes.
With closed up shoulder lugs, the Cooper AT3 again takes the cake, though with larger sizes, you’d find that Nitto Terra Grappler is little bit easier to maneuver, and that’s the reason why it has better speed ratings of up to H, whereas Cooper AT3 (XLT) gives you with the maximum of S.
Wet Traction
Wet traction is generated with water removal, as that’s the only way, because water is an in-compressible liquid and a tire would simply start to float if its not evacuated out in time.
And here two things are considered, grip and hydroplaning.
Wet Grip
Gripping is achieved with siping, as they suck the water (in their slits, literally), as the tread meets the wet surface, while the rest of the water leaves out through the grooves.
Cooper AT3 grips better here because of three main things, one, it offers a lot more siping, two, it’s siping design is more interlocking and three, it’s tread is flexible.
With larger number of sipes, more water gets removed at a given time and with a flexible tread, sipes get to squeeze with more pressure, so a larger volume of water is sucked in. This is further improved with the softer tread composition of the tire which enhances the sipes abilitiy to flex more.
Hydroplaning
On road oriented all-terrain tires like both I’m discussing here, may be more prone to hydroplaning due to their closed up tread design, so it’s important for these tires to have good water evacuation capabilities.
Both tires although offers longitudinal channels, there are no prominent paths for sideways water removal.
Though, still the Nitto Terra Grappler offers less closed up lugs, (so it’s better slightly), as Cooper AT3 has ridges placed over there, which blocks the lateral grooves almost completely.
Fuel And Tread Efficiency
Fuel economy and tread wear, both are affected by rolling resistance, (which is determined by the tire’s weight and the stickiness of the tread).
So here, although the Cooper AT3 comes up with softer composition which sticks on more, it’s joined up lugs still offer less rolling resistance values.
Nitto Terra Grappler on the other side, burns it’s rubber faster even though its a stiffer built. This is because its weight is 20 pounds heavier (comparing the heaviest size), and its average tread depth is smaller, even though both have similar upper thresholds.
That’s why you get a better mileage warranty for Cooper AT3 (XLT), with 60k miles (for all its LT sizes).
Ride Quality
The Cooper Discoverer AT3 tire is designed to provide a smoother ride due to its malleable composition, which allows it to sponge off more of the road’s imperfections and vibrations.
This tire also has whisper groove technology, which helps to reduce noise by using ridges between the shoulder lugs to prevent air from entering and hitting the walls (that’s how noise is created BTW).
On the other hand, the Nitto Terra Grappler has a stiffer composition, which makes it less able to absorb bumps in the road. Its slightly more open shoulder gaps also allow more air particles to enter and create noise pollution, as they strike the inside of the tire.
So overall, you get a less comfortable tire in it’s case.
Winter Performance
To improve their performance in snowy conditions, all-terrain tires may incorporate features like soft rubber compounds that remain pliable in cold temperatures, numerous sipes for added grip, and deep notches that can help the tire hold onto snow.
And considering all these features, it makes sense why Cooper AT3 offers better snow traction in comparison, though both of them have 3 peak mountain snowflake ratings.
It’s softer rubber compound is less susceptible to get frozen up and its snow vices grab the snow in a much more effective way.
Moreover, the full depth sipes are also interlocking all the way, and they offers better snow biting abilities.
Terra Grappler on the other side, is although not too far off, it’s still lacking because of it’s stiffer compound which don’t aid the sipes and bites with as much flexibility in comparison.
Off Road Traction
To excel in off-road conditions, tires should be able to perform on multiple types of terrains. Let’s consider the significant ones out of them.
Thick Mud
With closed up tread voids, both tires struggle a lot in clearing off the mud, which is very crucial for mud traction.
Mud has a thick composition, and if the tire is not properly voided, it would just stick in and would not leave, and mud to mud contact is the best recipe for getting stuck.
Though still out of these tires, Nitto Terra Grappler offers better traction.
This is because the tire is heavier and it’s lugs are more capable to sink deep in to the mud, providing better grip on the surface beneath.
Moreover, its staggered shoulders on sides with stiffer composition also offers better scooping of the mud, so it’s able to throw it backwards and move forward as a result.
On Rocks
On rocks you need biters and powerful sidewalls, (both from inside and out).
Now although both tires offer 2 ply sidewalls, the Cooper AT3 offers better. That’s because it’s lugs there are slightly thicker and covering more surface area.
So with lowered pressure, it offers much better lateral traction which is enhanced further with it’s softer rubber composition.
But still it lacks in the directional grip, and that’s where Nitto Terra Grappler comes in, with it’s (more number of) biters over there, in the form of traction notches, facing in all directions.
So considering both these traction components, I think it’s best to rate these tires equally here.
Soft Sand
You need a lighter and softer tire on sand, and that’s the reason why Cooper AT3 is a better suited here, especially if you get it in larger sizes (as Nitto Terra also offers SL and XL load ratings and they are lighter in comparison).
With lighter tire, combined with smoother sides, the Cooper AT3 basically does not want to dig in too much, and this helps maintain it’s forward moving inertia.
Moreover, as on sand, you always want to air down the tires, the Cooper AT3 providing a softer composition, molds over the sand in a better way, providing enhanced surface to rubber connection.
In closing
In conclusion, both are high-quality tire options that offer a range of benefits. The Nitto Terra Grappler G2 is a top choice for dry traction, hydroplaning, and off-road performance on rocks and mud, while the Cooper AT3 excels in wet road performance, snow traction, comfort, fuel efficiency, and tread wear.
Additionally, the Cooper Discoverer AT3 performs well on rocky off-road terrain, and excels on sandy dunes as well.
Considering all of these, I think it would be now easier for you to decide.
