tire/wheel size

67bbc · #1 (**permalink**) 07-20-2003, 08:00 PM

I know this probably has been posted before...for a 91 YJ with 3 inch lift. I am looking at 15x8 wheels, but unsure of the backspacing (I have seen 3 5/16 to 5 1/2). I to not want it to rub, however, do not want it to stick out to far either (trying to avoid the extended wheel flare sets for now). Also what size tire would work well with the 3" lift, 31/32/33"??? I was looking at the Mickey Thompson wheels but they have a 3 5/16 backspacing with -28.0mm offset. I was also considering stock TJ wheels in 15x8 but unsure of their backspacing/offset??? Your help is appreciated.[addsig]

MORGSTER · #2 (**permalink**) 07-20-2003, 08:00 PM

67bbc
I have a 1989 Jeep Wrangler YJ 4.2 I-6 running 33x12.5x15 Goodyear MTR's with a
5- inch lift. The wheels are Ultra brand aluminum 15x8 with 3 3/4 inch back spacing, that have performed well without problems (on or off-road, pumped or aired down) but I will be changing to a powder coated steel wheel (of the same size) when these tires wear out. (Polished was nice to look at, but the steel/powdercoated wheel will be less maintainance for me). I am now lifted to 5-inches, but there was a time when it stood with a 3-inch lift. Understanding that I had also installed TJ fender flares with the 3-inch lift (Which added additional room for tire clearance) there was never a rubbing or articulation problem with the 3 or 5 inch set up.

The thought of running 35-inch tires has crossed my mind, but it's not necessary for the rocks I crawl. I would want axle upgrades; with gear changes (More money in the pit) and the additional weight of the 35-inch tires on stock axles added concern as to breakage and bearing wear. (The breakage information is courtesy of friends that have made that change)

The Goodyear MTR's were a good choice. The first set lasted 40k miles (Probably had more life left, but looked very used) with good street performance, quite and smooth as can be expected from a Jeep. The off-road performance was impressive to say the least. The next set will also be MTR's barring any new, exciting products.

From my prospective, the 3 5/16 (Remember, I am running 3 3/4 without problems, but it’s close) back spacing should work although you might experience some tire to frame rub at full air pressure and increasing when airing down. Especially if you choose a tire with large sidewall lugs. There is some steering travel adjustment that can solve the problem but you do decrease the turning radius.

My tires do stick out a little, but not much more than my neighbors’ 31’s. The only complaint is the water spray from the front tires (Because of the width)(But the addition of the small TJ front flare extensions behind the flares would solve that) while running through puddles or streams, off roading with the top off. (The kids think it’s cool)

Note:
Any respectable shop will mount a tire/wheel combination and allow you to bolt it up to check the fit before buying.

Go to my picture page below to see the fit of the tires.

Good Luck and enjoy. 8-) [addsig]

ecor · #3 (**permalink**) 07-20-2003, 08:00 PM

The standard offset for a 15 x 8 rim is a neutral offset of 4" some consider there 3-3/4" to be neutral but it is really a -6mm offset. Either is for for a YJ running 33/12.5r15. If you want to goto a 35/12.5r15 you should step up to the 15x10 with a 3-3/4 backspace or a -44mm offset.

Hope this helps

[addsig]

steelerman · #4 (**permalink**) 07-20-2003, 08:00 PM

pretty much all after market 15x8's are good up to 35x12.5x15[addsig]

jackd0503 · #5 (**permalink**) 07-20-2003, 08:00 PM

Stock rims have about 5 1/2 in. of backspacing, which won't work with a 12.50 tire. I run 15x8 rims with 4.5in of backspacing on my 01 tj with 33x12.50 BFG A/T's and they fit perfecly with my 6in flares, which is important if your state regs require the tire tread area to be covered. The 15x10's i used to run stuck the tires out past the flares about an inch.[addsig]