Outer Limits 4x4 Board

Just wanting to hear peoples opoions about running 12.5 wide tyres with the standard 1.3? Also about the srubbing issue, on springs and steering ect....?

thats a VERY wide tyre!!! go 31x10.5 - its more common and the narrowness will help a ton.

What tyre are you planning on getting thats a 31x12.5???

I am still undecided, Just wanting to see if people think it is too wide on a zook.

Too wide in a 31 plus what tyre comes in that size?

Why do you want to run a tyre that wide? Tall skinnies work much better on Sierras and in fact most 4wds

I beleive boggers come that wide in a 31, or so some sites have said. This is what I am wanting to find out, how wide would be the widest you would run?

10.50 at the max. You need horsepower to make a bigger work well or good gearing. In a 31 it's a pointless size, a 35x10.50 is a great size though.

What sort of driving are you doing that needs a bigger?

ideally you'd run say, a 32x9.5 tyre... however some engineers frown on 32" tyres on a sierra axle... so 31's are what you're left with - and if thats the case the common size is 31x10.5r15 for most makes of tyre.

Maybe give more info on the terrain you drive, if its a daily, if its being engineered or not etc etc etc and people can give better advice to suit your situation.

He is in rocky according to his side bar thingy, so engineering tyres would hardly be a consideration


Personally I would run 31x9.5 on my Sierra if I could, but the tyres that come in that size are essentially not available in Australia. 31x10.5 works fine, just they do touch the springs a bit on full lock with a sensible offset rim. You can get massive offset, but then you get a large scrub radius, horribly wide wheel track and numerous other issues...

pro comp make an x terrain in 31x12.5r15 and the swamper bogger comes in 31x12.5x15 aswell

If you are only going wider for that PHAT look then just get big offset rims for extra track width and go 10.5" wide tyres.

I mainly drive rocks and mud, its a daily driver, dont know how long for tou. I dont really know what tyre im going with yet, I just wanted to know what everyone else thought. From what has been said I think I am going to go for the thinner tyre, if there is no benifts of having a wide tyre.

probably not as good a tyre,but the price might be right.....hankook mts used to have a 31x11.5.The procomps in 31x12 do look sick seen a sierra on them once.BUT id have to go with most others in saying 31x10,32x10 simex or the like(but due to driving rock aswell simex would suck) or even 33x10 if BFG still do them.
With a 10.5 most issues arent as bad as going 12.5s in terms of hitting springs on full lock or front standard shock tower and chewing inner sidewall up.

my 2c

Maxxis Mudziller do a 31x11.5x15 not so quiet on the tar awesome in the muc.
Depending on what u want to run em on . They hit on the springs on full lock with nt axles now have wt axles don't hit anymore there on 7" rims with -20 offset

Thornbirds come in that size too. I love the look of fat tyres but they are completely impractical. Even my 10.5 wide tyres just scrub my springs with max offset desert rat rims and the cops have pinged me for being outside the gaurds.

I have 31x10.5 wranglers and on my old 7" rims they would hit my springs pretty bad on full lock. I've now got 8" rims with -23 offset and they are perfect. It's still really close to hitting though, so if you wanted 12.5"s, you're gonna need pretty massive offset, which will bring on a whole heap of other problems