BF Goodrich KO2 34/10.5/17D vs 35/12.5/17E

[eaneumann]

I'm looking for opinions on these two sizes of tire. I'm pretty set on the KO2, but will consider others also. We live in Colorado, so snow rating is a must! These will be going on my daily driven Toyota Tundra Crewmax. I haven't bought wheels yet, so I would also consider other sizes. The truck has a 3" lift. I tow 6-7k LBS. about once a month. We drive about 30k a year, 60% highway, 30% dirt/gravel, and 10% hard trails that the truck probably shouldn't be on. I would say it gets used for serious off-road more than the average full size. My two main concerns are the tires looking too small and the tires being too large that I loose a lot of my drivability. The 34" is D rated and the 35" is E rated. Opinions? I was really looking for a tire that was as close to a 35" and as narrow as possible.

 

[skysix]

if don't NEED the extra weight D should be fine for your truck, sidewalls are strong enough except on sharp rocky roads like the Dempster highway. - get it weighed by axle when loaded to check. The extra 2" width will be a hindrance on ice (less grip) and in mud (resistance) but better for sand (flotation). Not enough for snow flotation though (44x15.5 at 4 psi will do that).

 

[eaneumann]

This truck will be traveling the Dempster highway in the next year or two. Will probably need another set by then. I had Goodyear Duratracs at one point and the sidewalls just couldn't hang.

 

[Ducky's Dad]

I have had a bunch of BFG ATs and Kos on several trucks and I don't buy BFGs any more. Two of my trucks are running Toyos and the other has Nitto Terra Grapplers (found right size at great price). All current tires are Load Range E, including the Toyo AT-2s on my 2008 CrewMax. My Tundra has stock suspension with ProComp shocks and leveling in front that improved the handling tremendously. It has the factory 18" wheels but I would much rather have 17" wheels for the extra sidewall flex with my stiff tires and because all my trucks could then use the same tires in a pinch. My BFGs suffered tread separations and caused death wobble on one of my trucks. Twice burned by BFGs, I'm not going back. Toyos are my tire of choice now, have had MTs and AT-2s, but the RTs look like a great all purpose tire for your type of driving. The Tundra ride is soft enough that I would not hesitate to get Load Range E.

 

[Taco2FJ]

I just bought 1 34x10.5r17 for my FJ with a long travel front end to see if it would fit. I have a ton of travel so a 33 looks pretty small, but I can't go much bigger because I'll rub at full compression when running in the desert.

At my Discount Tire, measured a unmounted circumference of 3 tires and compared to my half worn KM2s in 285/75r17. Measurement were done 4 times to be as accurate as possible.

KO2 34x10.5r17: 102.5"
KO2 285/70r17: 102.4"
Duratrac 285/70r17: 101.8"

So I took one 34 home, and then out in the desert for testing. Mounted separate of the FJ, circumference went to 104.1" or a 33.1" tall. Under load of the FJ front with bull bar, winch, full skids, frontrunner rack, the 34 was a true 32" tire at 33.5 psi. and it still rubs, but thats my problem, hopefully this helps you though.

They had a 35x12.5 there, I'll measure it up for yea this weekend so you can get an idea.

But I think of the 34 and the 285/70 as pretty much the same height, just in a 1/2 inch thinner and lighter load version.

 

[eaneumann]

I just bought 1 34x10.5r17 for my FJ with a long travel front end to see if it would fit. I have a ton of travel so a 33 looks pretty small, but I can't go much bigger because I'll rub at full compression when running in the desert.

At my Discount Tire, measured a unmounted circumference of 3 tires and compared to my half worn KM2s in 285/75r17. Measurement were done 4 times to be as accurate as possible.

KO2 34x10.5r17: 102.5"
KO2 285/70r17: 102.4"
Duratrac 285/70r17: 101.8"

So I took one 34 home, and then out in the desert for testing. Mounted separate of the FJ, circumference went to 104.1" or a 33.1" tall. Under load of the FJ front with bull bar, winch, full skids, frontrunner rack, the 34 was a true 32" tire at 33.5 psi. and it still rubs, but thats my problem, hopefully this helps you though.

They had a 35x12.5 there, I'll measure it up for yea this weekend so you can get an idea.

But I think of the 34 and the 285/70 as pretty much the same height, just in a 1/2 inch thinner and lighter load version.

Thanks for the info! What you you think of an E rated vs D rated? I'm really leaning towards the 34 just because of the width. Thanks again!

 

[Taco2FJ]

So, I ran an the old MTR in 285/70r17 that was D rated in death valley, rubicon, moab, tellico, and a ton of highway to get to all these trails and then the current KM2 285/75r17 which is E rated on the same stuff.

Normal driving with E rated is rougher than D rated (obviously) but in a rattling sort of way. I feel like I wanted to run lower psi more often with the E rated when on long corrugated trails over the D rated which I was pretty happy at about 25 psi to soak up dang near everything.

Now when I am loaded to the brim with the ability to overland for about 6-8 days between needing fuel, E rated starts to get squished a little more, and feels more compliant.

Now with the Tundra of yours, you will probably not notice the firmness of an E rated as much as me, my buddy's tundra has E rated KOs and they feel very planted, but not overly firm on gravel roads.

As far as width, .45 inches is the difference between a 285 and the 10.5. I get it, I think the 34x10.5 is an almost perfect tire for toyotas and jeeps that want to doing everything relatively good. It's tall, it's stock width, it's D rated to keep weight down (86.5 lbs on BBS 17x8 rim), triple peak rated, with a sidewall that the titanic wishes it had, which is why I took the chance and bought one to test. But the KO2 34 definitely does not look nearly as pizza cutterish (yea it's a word now) as the KM2 255/80r17.

I honestly thing the size for you should come down to the suspension you have and the terrain and speed you want to do the best at. I have a tall truck, and could fit a 36 easy on gravel roads, but up travel is whats going to get you. If you already have a 35 that fits good, then run a 35, if you are looking try to get to a 35, I'd suggest the 34.

Hope I didn't ramble too much, been build custom cars and 4x4s for years, and I have to really think about what's pertinent and what is just unnecessary.

 

[leelikesbikes]

D

if your not towing or hauling super heavy go with a D, the E doesn't get you any more sidewall plies, just tread plies and a rougher ride, all the ko2 sizes have a 3 ply sidewall. I run D tires on my 2500, but in a 37 they still have plenty of load capacity, but a far better ride than an E. I didn't know you could fit 17's over the brakes on the new tundras? that's cool if you can, I prefer more sidewall for offroad, I wish I could fit 16's on my dodge:sombrero:

 

[Thirsty]

I put a set of the 34x10.5 tires on my jeep. Mounted on 8.5" wheels they fit without a lift. They drive great and my gas mileage was basically in phaised. I can't say enough good about them.

I did add a little more than an inch of lift a few weeks after getting the tires.

 

[eaneumann]

Good looking Jeep! Thanks for the input everyone!

 

[UncleJimmy]

I'm looking for opinions on these two sizes of tire. I'm pretty set on the KO2, but will consider others also. We live in Colorado, so snow rating is a must! These will be going on my daily driven Toyota Tundra Crewmax. I haven't bought wheels yet, so I would also consider other sizes. The truck has a 3" lift. I tow 6-7k LBS. about once a month. We drive about 30k a year, 60% highway, 30% dirt/gravel, and 10% hard trails that the truck probably shouldn't be on. I would say it gets used for serious off-road more than the average full size. My two main concerns are the tires looking too small and the tires being too large that I loose a lot of my drivability. The 34" is D rated and the 35" is E rated. Opinions? I was really looking for a tire that was as close to a 35" and as narrow as possible.

I know this thread is a little old, I am looking at the same tires for my Tundra. I was wondering if you could tell me what you went with and what wheels you were looking at in 17". If you could post a picture that would be great!

THanks.

 

[eaneumann]

I was looking at 17"s because I wanted the OEM Rock Warrior wheels, could not find them for a decent price. The previous owner of my truck kept them when he traded in. I'm currently running the OEM SR5 wheels in an 18" that were on it when I bought it. I went with 285/75/18 Toyo AT2 Xtremes. The tires are wearing very well and did pretty good in the snow. I had the chance to drive another truck with KO2s in the snow and I think the Toyo did better. I did puncture a side wall today, but I think it was just bad luck. These are a 10 ply.

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[seans]

Truck looks good.
I have SR5 I'm about to start building. Looking for some rock warrior wheels too but not finding any for a reasonable price either.
Any rubbing with those 285/75/18 on the oem wheels?
Thanks

 

[eaneumann]

Truck looks good.
I have SR5 I'm about to start building. Looking for some rock warrior wheels too but not finding any for a reasonable price either.
Any rubbing with those 285/75/18 on the oem wheels?
Thanks

Thanks! I'm running Spidertrax spacers in the front, King 2.5 front/rear, and Camburg UCAs. I also did the body mount chop. I have some very minor rub on the plastic wheel liner in the front. The body mount chop is not a big deal. If you can't weld, have a welding or body shop do it for you. Relentless Fabrication offers plates that are pre cut.


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[joshjan]

I have the rock warrior wheels, 1.5 inch bora spacers and 315's in load range d. I like them better than my old 285 e range tires. I do notice the extra height when towing. It's not terrible but noticeable. I have a 3 inch spacer lift, soon to be replaced, and all I had to do is remove the mud flaps and lower inner fender liner. No body mount chop.