Both the Sumitomo Encounter A/T and BF Goodrich KO2 are very different all-terrain tires, where the Sumitomo A/T is great for mild off-road and has excellent on-road manners, while the BFG KO2 can conquer even the toughest of rugged tracks with its deep biters. Though the newer tire in town is getting a lot of hype, lets see why!
Being a tire engineer, from my perspective, the BF Goodrich KO2 shines off road with it’s aggressive sidewalls, both from inside and out, hence its a superior option for severe off-road terrains. Whereas, the Sumitomo Encounter A/T handles pavements better, with it’s smooth comfortable performance providing superior traction, fuel economy and wear. Being all season it brings 3PMSF ratings as well, though its also available on KO2.
(Highlighted links above contain their detailed review, it’s recommended you check them out first, for better understanding).
Table of Contents
Sizes Info
Sumitomo Encounter AT comes in 15 to 20 inches rim sizes with following specs.
- They have speed rating available in Q, R, S and T.
- Load Ratings: SL, XL, C, D, and E.
- Weight Range: 34 to 84 lbs.
- Tread depth varies form 13 to 20/32″.
- Warranty: 60k for all sizes.
BF Goodrich KO2 on the other hand, offers 90 sizes in 15 to 22″, with following specs:
- They offer speed ratings in: R, S, or Q.
- Load ratings: C to E.
- Weight range: 35 lbs to 67 lbs.
- Tread Depth: 15/32″ on all sizes (except 4).
- 50k miles warranty.
(It’s amazing to see that BFG KO2 with such durability, weighs lighter, comparatively).
Durability
Off-road tires are made strong with powerful internal construction. Though on the outside, they also have a cut resistance rubber and deep tread voids that help out things further.
The BFG KO2 offers a stronger overall construction, with 3 ply polyester carcass, 2 wide steel belts layered on top, and 2 nylon cap plies “spirally wound”, whereas the Sumitomo offers with just 2 layers of polyester, 2 belts and a single cap ply of nylon.
Though it offers thicker rubber on top, going up to 20/32″ whereas the max you get on BFG, is 15/32″.
Tread Design
The BF Goodrich KO2 is a tire that truly stands out from the crowd, with its three interconnected ribs and wild outer shoulders.
Lets start things from the middle, here there are 3 main ribs containing worm like blocks.
Each block is equipped with full depth interlocking sipes, which enhance the tire’s off-road performance by splitting open the blocks (all the way) and providing additional grip.
It’s self cleaning grooves feature dual stone ejectors and sharp, full depth notches placed at various angles to improve traction on all types of rough terrains.
On sides, the tire features staggered shoulder lugs, equipped with mud scoops and sharp full depth notches, giving it a wild, off-road-ready appearance.
The prominent lateral spacing between these, which carry bold stone ejectors go all the way, towards sidewalls.
Both differently shaped shoulder lugs basically join together there forming sharp slanted biters in between.
On the other side, the Sumitomo Encounter A/T is designed very differently, though it also contains 3 ribs in the center and elongated shoulder lugs on sides.
The ribs in the middle are packed up together and are placed in wide circumferential grooves, which separate the shoulders.
All these ribs carry very small lugs (compared to sides), with full depth siping pattern and biters.
And with closed up arrangement they make very narrow internal longitudinal grooves.
Moving towards shoulders, the lugs are although not staggered, each lug is serrated on itself, so they still provide good enough lateral bite off-road.
Moreover these lugs carry more aggressive siping (compared to the middle) and with it provide amazing handling capabilities on wet.
Towards sidewalls, the tire makes M shaped lugs there, which are although not so thick are still pasted on a good amount of area.
This basically helps the tire when aired down to lower pressure PSI.
Dry Performance
In order to understand overall dry traction, we have to check out directional and lateral grip separately, one by one. Let’s dig in.
Directional Grip
With a more streamlined design, the Sumitomo Encounter A/T yields a better directional grip.
Basically, this type of grip has to do with the central lugs, as they make the most contact with the surface “when moving on a straighter path”, so with closed up lugs there, tire is able to stop quickly, with shorter braking distances.
BF Goodrich KO2, on the other hand, although offers a consistent pattern in the middle, it’s wider grooves don’t allow a lot of rubber to stay connected with the surface, and so overall friction and grip is compromised.
Lateral Grip
Sideways grip, or lateral traction, refers to a tire’s ability to corner, and is based on the performance of the tire’s sides, or you can say shoulder lugs.
Sumitomo Encounter A/T, again with its compact shoulder ribs, offers more desirable results. The tire basically provides bigger lugs there (compared to the central section), and with minimal tread features, they make a lot of contact with the road, enhancing lateral traction.
BF Goodrich KO2, in comparison has wild shoulder lugs, with multiple full depth notches, and surrounding aggressive tread voids, that’s why it lacks here by a lot.
Wet Traction
Wet performance for off-road tires can be difficult to achieve due to the challenges of balancing wet grip and hydroplaning resistance. Let’s discuss them both.
Wet Grip
One of the main reasons why all-terrain tires may not perform as well in wet conditions is due to their low sipe density, but both of these tires feature plenty, so we have consider other factors like the tread composition and design.
And so with dual siping design and a softer composition, the Sumitomo Encounter A/T is going to provide you with better efficacy.
It’s interlocking sipes, especially on shoulders (as they provide the most handling traction), don’t get hardened up with sharp turns and sudden braking, and it’s tread compound already provides a lot of flexibility as it consists of large silica percentage.
BF Goodrich KO2 in comparison has stiffer siping, and they can’t flex enough to provide decent wet wiping abilities.
Sipes basically suck water particles in by expanding and contracting, and with less elasticity, they cant do that.
(BFG KO2 sipes are basically better optimized for off-road traction, especially on rocks, as you’d find out in the related upcoming topics).
Hydroplaning
Balder tires have better water evacuation capabilities and so they “resist” hydroplaning more (which occurs when water comes in between the surface and the tread).
The BF Goodrich KO2 with consistent 3 rib design in the middle, creates a map of interconnected grooves, which allow water to leave off in any natural direction it wants to.
Sumitomo Encounter A/T on the other hand, although, is pretty closed up, it’s softer tread is still able to gush out water with greater pressure, so it’s wet traction is not compromised at all as well.
Fuel Consumption
The fuel usage of a tire is related to its rolling resistance, which is influenced by the tire’s weight and its ability to stick to the surface.
The BF Goodrich KO2 although, is lighter in weight, the tire still has more rolling resistance in comparison. That’s because with wider grooves, all of it’s lugs have to bear more pressure on them.
Meaning, the overall weight of the tire is distributed on a fewer lugs, so they get to rub off with the road with greater force.
Sumitomo Encounter A/T, in comparison, even with it’s heavier construction, keeps rolling resistance at bay, because of it’s joined up design, distributing that weight evenly across all over its tread.
Tread Life
Tread life is although dependent on a lot of variables including driving style, if we neglect all of them, the tread structure becomes the most important factor to consider.
The BF Goodrich KO2 although, has a lot more rolling resistance values, as we’ve learned in the section above, it’s stiffer composition, still allows it to have decent tread wear life.
But of course, with a more streamlined design, Sumitomo Encounter A/T is more resistant to wear overall, and that’s why it comes with 10k more miles, in tread warranty.
Ride Quality
The tire’s structure and tread design both play a significant role in tire’s ability to absorb road impacts, and noise generated, which in turn affects ride quality.
Tread Noise
In terms of noise, both tires feel the same (subjectively) but only with slower speeds, as on highways, it gets pretty clear that Sumitomo Encounter A/T provides a quieter ride.
On BF Goodrich KO2, after crossing 45mph, you start hearing a wobbling sound, though its not that distracting as it dissolves into a background noise.
Though out of both tires, one thing is considerable, as the tire wears, the KO2 does not go bad, and this has to do with it’s dual compound structure of the rubber, with harder layer below the softer.
(However, you do get a more limited wet traction for sure).
Sumitomo Encounter does get louder with wear, but the tire would be still quieter comparatively (tested up to 40k miles).
Comfort
Ride comfort is one of the main reasons why all terrain tires exist, otherwise, why not get a mud tire, with more off road capabilities.
The good thing is, a lot of A/T tires coming in are comfortable enough. And BF Goodrich KO2 is barely making that list, if it is.
Its 3 ply spirally wound nylon cap plies basically make it’s sides pretty stiff, and so bumps aren’t absorbed as effectively as its competitor.
The Sumitomo Encounter A/T basically does better as it offers a softer rubber layer, which is also very thick, going up to 20/32″ (almost 5/32″ larger in comparison). So with this, its able to settle down on-road vibrations effectively.
Winter Traction
The malleable rubber composition of Sumitomo Encounter A/T has better thermal adaptive properties too, so it’s able to bear more negative temperatures of cold without freezing up.
It’s basically a feature that winter tires have, (actually they do it better, that’s why they are so soft).
But does that make Sumitomo’s boy better in comparison? Well not really.
The BF Goodrich KO2 makes better snow to snow contact. It’s tread has interconnected grooves which are very effective in trapping snow particles. That’s why this tire is also awarded with 3 Peak Mountain Snowflake rating, though its also available on Sumitomo Encounter A/T.
Moreover, KO2 features a narrower tread, and with smaller width it’s able to put more pressure on the snow, lodging it in it’s grooves with more force.
Off Road Traction
All-terrain tires try to maintain a good balance between on-road and off-road traction, to navigate various terrain types effectively, though with more aggressive tread design and durability some do better overall.
Let’s check out all these terrain one by one.
On Mud
Mud is the toughest of all terrains, and here self cleaning grooves are crucial.
Sumitomo Encounter A/T has lugs very closely arranged, and although it has tread depth going up to 20/32″, the lugs joined together from underneath (they actually run in pairs), so mud is not efficiently cleaned out.
BF Goodrich KO2, in comparison, is pretty bald, so it’s not a surprise that you get better self-cleaning capabilities there. Moreover, it offers huge mud scoops on shoulder blocks, and it’s sidewall lugs are thick enough to provide the needed digging.
On Rocks
On rocky terrain, durability and strong traction are key factors for successful performance. And both are given best by beast of a tire, BF Goodrich KO2.
This tire offers 3 ply sides, and as mentioned above, thicker sidewall lugs, so while you crawl on challenging terrains with confidence, the lugs provide extra biting needed, especially when you air down the tire to lower PSI.
Sumitomo Encounter A/T lacks in biters, and it’s less aggressive shoulder lugs aren’t capable of providing as much lateral traction as the KO2.
On Sand
It is important to lower air pressure in tires when driving on sand to increase the overall tread print and improve traction.
Basically when you lower the air pressure, tires get to float on sand in a better way, and there’s less digging.
That’s why even though the Sumitomo Encounter A/T weighs a lot more (going up to 84 lbs), with closed up lugs, that weight gets divided more uniformly, and this tire gets to provide better forward momentum.
BF Goodrich KO2 on the other side, with sharp shoulder lugs, and 2 ply spirally wound nylon caps underneath, digs in with more force, so its a challenge maneuvering this tire especially on slopes.
On Gravel and Dirt
When driving on gravel, stones can easily get stuck in the tire tread and cause damage to it, which can then impact the tire’s handling and directional traction.
To prevent this, although both tires have cut resistant rubber, the missing stone ejectors in Sumitomo Encounter A/T does not allow it to perform better, comparatively.
BF Goodrich KO2 on the other side, offers dual stone ejectors, conventional ones are placed on the outer margins (b/w shoulders), while there are others, triangular (shaped) ones that can be found in outer longitudinal grooves.
Both of these ensure, it’s tread remain clean even during high speeds on thick gravely and dirt filled roads.
Conclusion
Sumitomo Encounter A/T is a more on road oriented tire, so it’s much better in dry and wet gripping performance areas.
You also get to have a longer lasting tread, better on road comfort, fuel economy and steering response, though off road, it lacks in comparison. And that’s where BFG comes in.
BF Goodrich KO2 is the most durable tire you can get, that’s why I rated this tire for it, in my list of top all time A/Ts, so with stronger design its capable of going on to challenging terrains.
