Originally Posted by apresas
i've been reading i need 4.5 backspacing on a wheel to run a 33" tire. Is that correct? also whats the difference in 33x12.5x15 and 305/70/16. obviously i know the wheel size. theres so many formats of tire sizes. it blows my mind.
You can go up to 315 on a 5.2" backspacing and a 2.5" lift... as that is what the AEV-spec wheels are, and you can go right up to 37's with that combo. The factory wheels are 6.5", and many aftermarket wheels are 4.5".
You don't need 4.5 backspacing to run most 33's... unless you are getting some really wide ones. You don't actually need a lift either.
For the tires... the '305' in the above is the width in millimetres, which converts to approx 12 inches. The '70' means the sidewall is 70% the height of the tread width... so .70 x 305 = 213mm or 8.4 inches. On a 17 inch wheel, you end up with 17 + 8.4 +8.4 to get 33.8 tire height.
Now, this assumes the manufacturer's specs are accurate...and they often are not close at all. Lots of 33" tires come in at 32" mounted. My Duratrac "35s" are more like 34 and a bit.
For wheels... ideally you want to find a Wrangler-specific hub... these are called 'Hub-centric' and fit like a factory wheel. Others that have larger hub holes are called 'lug-centric' and use your studs to align. You are less likely likely to run into balance issues or busting a wheel if you have hub-centric wheels.
AEV makes only a few styles, but the advantage is they are Wrangler-spec, have 5.2" backspacing and will work with lots of tires. There are 100's of wheels that will work...
If 33's are all you want... just get some nice wheels to widen it out a bit and you are all set.