33x12.50s on 15x7 whels...opinions please

[Tiffster]

OK, here is my dilema: I am gettin new tires (hopefully MTRs) and am moving up to 33x12.50s. I just got new wheels and tehy are 15x7 with 4" backspacing. Now I have several friends who run their 33x12.50s on 15x7 rims with no problems, but it has always been told to me to keep the tire width within 4" of the wheel width.

I talked with my good buddy Scooter at 4WPW and he said he would stick with the 15x7 wheels as long as I watched the tire pressure to prevent funky wear patterns. And hey, I would love to not have to by new wheels again (would be the 6th set on my XJ...argh!!!!)

So what say the ILJ brethren? Please don't preach, give me some facts and info to deal with.

[The Man with the Plan]

Minimum wheel width recommended by tire manufacturers for 12.50" wide tire is actually 8.5". You will get a funky wear pattern regardless of tire pressure with that narrow of a wheel.

[Tiffster]

So Scooter is smoking the crack again?????

[The Man with the Plan]

I think he was just trying to save you from spending more money.

I'll tell ya' this though, unless I keep my 35x12.50 SSRs below 25 psi, I get terrible wear on my 8" wheels. Granted, my TJ probably isn't as heavy as your XJ, so that is in your favor. However, the reason the tire manufacturers put a limit on rim width is for bead retention. Generally a narrow rim with a wide tire will hold a bead quite well. But, there is a limit. The limit is when the bulging of the side-wall causes the bead to fold. The result is poor bead retention.

[Eric Ruhl]

I had 33x12.50's once but I was at the other extreme... 10" wide wheels and that sucked. Well, great for on-road but sucked for off-road. I'd run an 8" rim with 12.5" wide tires.

[Chris S]

I know of at least a dozen people (myself included) who run 33x12.5s on 7" wheels with no funky wear problems. It is critical to find the correct air pressure, and the best pressure is usually a bit lower than you would expect. The down side of this is that the lower pressure makes for a "floating" sensation when cornering, and results in your tires wanting to follow every little bump and groove in the road.

I have had some bead leak problems with my OEM 7" steel wheels, but that is because of the junky welds done right where the bead sits. I also play HARD :D.

I say try the 7s and see how you like it. If you have problems then change wheels, but don't spend the $$$ until you know you have to.

[JOKERAL]

Well in the poll I voted NO to the 7" wheel. Now as stated in other posts people are doing it and getting away with it, but they do it by playing with tire pressures, sacrificing handling and issues with the bead, and it is against manufactor recommendations.

Sounds to me like a safty issue, and should be avoided. Get some cheap steel wheels for around 30 - 35 bucks in the proper size and be safe.

Jokeral

[thew_77]

Yea look at the Firestone fiasco here on account of tire pressures. I worked as a mechanic in college, and we always went with what the sidewall said it's just safer. As for rims it's your opinon but running wide tires on narrow rims will cause uneaven wear on the tire causing premature wear-out.