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Discussion Starter #1
For a while now I've been trying to decide between 245/75/r17 vs 265/70/r17 tires (basically the same height). I've read through discussions about tire width on the forum and thought I'd add a couple things that helped me decide (for those who spend entirely too much time thinking about such small issues like me). :)

The main debate is whether tall/fat tires with a larger contact patch perform better than tall/thin tires with smaller contact patch. One the one hand a fat tire will exert less pressure per square inch than the thin tire. However, because of the larger surface contact, it should provide more friction, and as a result traction. One the other hand thin tires exerts more pressure per square inch underneath the tire. As a result, it can "bite" into the road better as some would argue. The reality of what performs better it depends on the conditions you drive in. Here is a white paper by a company called Expeditions West that makes the case that a thin tire is a superior choice for all off-highway surface conditions with the exception of deep, soft sand or mud. I would add to this powdery snow. The other factor is traction when making turns and that wider is better, which I've learned has much to do with the composition of tires and stiffness of the sidewalls as the width. Here is a good discussion from a racing forum on on this. Friction is also related to gas mileage, and I think that also depends to a large degree on the composition of the tire as much as the width.

In the end I'm probably going with the wider 265/70 tire (probably Goodyear Duratracs). I used to do a lot of offroading but most of my driving these days is either around town or on the highway towing a small travel trailer. I just think the 265 width looks better on the XK especially with the wheel setup I'm planning (8" wheels with +10mm offset), and I don't think the 0.79" difference in width between 245 and 265 will make a noticeable difference in my performance or gas mileage.

Again I hope this is helpful for anyone else on the fence.
 

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Performance comparison aside, there are also clearance issues created by wider tires.

Once you go wider then 265's you will have clearance issues when you turn your wheels all the way in one direction or the other, which means you either have to add spacers or have to buy custom rims with enough back-spacing & offset to allow enough clearance for the wider tires.
 

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Discussion Starter #3
Good point. With 265s, a +10mm offset and 2" lift I'm anticipating having to do the pinch weld to avoid rubbing.
 

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Good point. With 265s, a +10mm offset and 2" lift I'm anticipating having to do the pinch weld to avoid rubbing.
I can tell you that I have the 2 inch RC lift with P265/70R17's TOYO Open Country All Terrains - my rims are 17 x 8 with 5.5 inch back spacing and I don't rub at all and I didn't have to do any other modifications for clearance. Prior to the TOYO's, I also had BF Goodrich 265/70R17's Rugged Terrain T/A's and didn't rub with those tires either.
 

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Discussion Starter #5
Thanks good to know. How close does your tire come to the plastic of the wheel well? I'm guessing it's less than width of a finger?

With 8" rim and 5.5" backspace that mean's you have +25mm offset. From what I read on the forum guys with that setup (with 265/70s or 245/75s) usually don't need to mod anything. Anything 0mm offset or negative will rub. I'm not sure about +10mm offset though, which on an 8" wheel is 4.9" of backspace. One thing that was counter-intuitive for me at first is the smaller the backspace/offset and the further the tire sticks out the more it rubs in the wheel well. That makes sense to me now given the concavity of the wheel well.
 

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Thanks good to know. How close does your tire come to the plastic of the wheel well? I'm guessing it's less than width of a finger?

With 8" rim and 5.5" backspace that mean's you have +25mm offset. From what I read on the forum guys with that setup (with 265/70s or 245/75s) usually don't need to mod anything. Anything 0mm offset or negative will rub. I'm not sure about +10mm offset though, which on an 8" wheel is 4.9" of backspace. One thing that was counter-intuitive for me at first is the smaller the backspace/offset and the further the tire sticks out the more it rubs in the wheel well. That makes sense to me now given the concavity of the wheel well.
Not sure zing, I'll check a little later on and get back with you.
 

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You literally asked if a wide screw driver is better than a thin screwdriver...

Both types are tires in your question, and it all comes down to both being tires. Tall, thin tires have been known to be good in very sloshy mud stuff. While fatter tires have good float, great on sand which is loose but not sloshy.

265/70/R17 works just fine with all the 2-3" kits, the tread type is where you may or may not see a difference depending on what you want to get out of it.

Good old standard is BFG AT KO muds. These are generally the go to tire for most everything and will not wear very fast, mine survived almost 50,000 on my Cherokee.

Firestone is actually coming back into relevance again for SUV tires and have a decent line up for a good price.

Where do you plan to drive really?


Dave
 

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Discussion Starter #13
You literally asked if a wide screw driver is better than a thin screwdriver...

Where do you plan to drive really?
Dave, I plan to drive mostly around town and on the highway, but a few times a year I either go skiing or camping where I want to be ready for all kinds of snow and moderate offroad. I like the look of Duratracs and the reviews seem consistently good so I plan to go with them in 265/70/17s. Thanks for your input.
 

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Too easy, we have our experiences with what is comfortable for the drive.

I have also heard nice stuff about Duratrac's . Besides, air-down and slow makes every tire useful :)


Dave
 

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I recently did a 2.5" lift and was running 265/70/17's all year until snow came. I tow a 21 ft hybrid trailer a lot in the summer and boats quite a bit, I originally liked the feel, but as my tires wore down, I felt it was floating ( hydroplaning) scary at times during heavy rain on pavement and highways. Especially while towing. They were getting down to maybe 60% so I'm sure that had a big factor, but for this spring I am leaning towards putting on 245/75/17's. Thinking it will help with the sketchy hydroplaning and maybe better for towing?, I don't know. Better on gas I am assuming.
BTW, I had no rubbing or needed to do anything with the 265/70/17's.
 

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The size of the tire doesn't have everything to do with it, what tires were you running? One of the mistakes people make is going cheap on tires. Spend money on good quality tires, the bargain basement tires aren't usually going to preform well. I'm all about saving a buck but the tires are the only thing connecting you to the road. If you're down to 60% tread after only one season, there's some serious issues with your tires. If you're towing a lot, consider moving up to an LT tire instead of a passenger tire. Improper inflation and load can significantly wear even the best of tires. I've gotten great wear from the stock Goodyear Forteras, over 75K miles, however they aren't the best for off road use. If you're going to be staying on road and doing a lot of towing, with occasional off road use I'd suggest you look at the Goodyear Wrangler Silent Armors. It's a great all around tire with a great warranty and they're available almost everywhere. The only issue with tire width is in snowy conditions, and short of dedicated snow tires nothing is going to be perfect in snow. I'm currently running the Nitto Ridge Grapplers in 265/70/17 and they have been outstanding performers in everything from Outer Banks sand, thick Virginia gooey mud, rocky trails in the GWNF, and the recent 10" of snow. They are load E tires, and they are a bit harsher than the stock rubber, but after 6500 miles, they look like they've barely worn. The sweet spot for me seems to be 34 psi and I rotated them just shy of 5K miles. I've run Goodyear DuraTracs (not on the XK) and they were great tires everywhere. I have a buddy who is running the Falken Wildpeak A/T3W and he says it's the best tire he's ever had on his JK.
 

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The tread pattern makes a huge difference as well. Read up on reviews and whatnot to make sure the tires you are getting are good at channeling the water away and maintaining good grip in wet conditions if that is what is most important to you. If a tire is optimized for rocks, as an example, their performance is going to suffer in ice or wet conditions.
 

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Usually one can assume, that the manufacturers have done their homework to recommend the optimal tires for the vehicle they constructed and also ran numerous tests on them. (That does not mean that the recommended manufacturer is the best,because this is taken under consideration of the best deal they get! Just the sizes)
However, since they use statistical information about the averages user, the individual user can change his choice.
Sizing a little up or down without changes to the suspension is usually no problem.
One than can take into consideration the weather- lots of rain, mud, offroad, highway, city and what else can help choosing.
The other factor is fuel economy- the wider the tires, the more consumption.
One can find nice statistics about tires at online tire dealers which gives indications on the fuel economy, wet road capabilities and noise emission as well as other experience values based on independent surveys and tests. (From A-G, where A is best)
I am certain one can find those also elsewhere in the internet but I am too lazy to google now.
The other thing to think about is, that most RACING vehicles (OFFROAD) actually use thinner tires then the average Offroad enthusiast.
Because in reality most go for the looks and not the practical purpose...
Where one can gain advantages is in the correct choice of tire tread - not so much the width.
So choose wisely in the tread and you are already a winner. Then choose on milage (your wallet speaks), rule of thumb here is- the better the grip, the faster the tire uses up.
However, if choosing thinner ones, one can compensate for this by paying less.
The only reason to choose wider tires would be an extreme soft surface, or as said, the looks.
But using those big foots then on roads and moderate Offraod terrain (as we probably do 99%) the wide one only gives disadvantages, and worst, in situation where one really needs a good grip, such as thunderstorms, snow and in comfort.

This are just my 5 cent :)
 

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If you are off-roading at all, you generally want a wider tire to maximize your 4WD system's effectiveness.

As for tire size, that would depend in large part on the lift your are running.

Personal preference and the look/stance you want also plays a part obviously.

It's really not that complicated though - and I would agree with Rick in saying that tires are not an area where you want to be cheap.
 

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Bfg 265/70r17 ko2

I can tell you that I have the 2 inch RC lift with P265/70R17's TOYO Open Country All Terrains - my rims are 17 x 8 with 5.5 inch back spacing and I don't rub at all and I didn't have to do any other modifications for clearance. Prior to the TOYO's, I also had BF Goodrich 265/70R17's Rugged Terrain T/A's and didn't rub with those tires either.
BigBlue,

I have an opportunity to pick up a <1,000 mile set of BFG KO2s. Since stock backspacing is 6" inches I should order a 1" spacer?

Thanks in advance.
 
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