Topic: Biggest Tire to fit on 15x7 Rims?

[dunklervogel]

I have stock 15x7 rims on my 97' Wrangler SE.  Going to get new/bigger tires and was wondering if I'm gonna have to purchase new rims or not.  Have 30x9.5  atm was looking at 31x10.5 prolly not much bigger than 32s possibly.  Figured I'd ask on here before heading in to the tire stores.  Thanks in advance for the help!

[JeepManMarc]

I have stock SE wheels on my 97 and Im running 31 x 10.5's with no issues.  I saw pics on jeepsunlimited.com of a guy running 33's on the stock rims also.

[dunklervogel]

Cool thanks for the reply.  Just wondering, looking at your rig, are you running stock suspension?

[JeepManMarc]

Yes I am, everything is stock except the tires and tow hooks, just bought it less than 2 weeks ago.

[JeepManMarc]

Here you go, this is GzrGlide from www.jeepsunlimited.com he is running 33 x 10.5's on stock SE rims:

[chrisfranklin]

33 x 10.5's on stock SE rims

Those stock wheels are 15x7s?! Dang  :shock:

[might4banger]

If you have sufficent lift... you could go with some 34x9.5 TSLs

[GzrGlide]

Here you go, this is GzrGlide from www.jeepsunlimited.com he is running 33 x 10.5's on stock SE rims:

I know this is a little late, but thought I'd throw it in for future reference.

The typical rule is that you can run a tire that is 50% wider than your rim width. So 7 inch wide rim can run up to 10.5 tire, 8 inch rim = 12.5 wide tire. You get the idea.

Also check the tire companies websites. Some of them list the minimum width rim that a tire can be installed on. Many tire dealers won't install a tire on a rim that the tire company says is too narrow.

hth.

[jagular7]

I'm running 34x10.5 on 15x7 rims w/3.75" bs. The shallower bs provides the space necessary for a taller and wider tire in the wheelwell with enough spacing to keep off suspenion and body parts.



Do note that if you go with a different tire and wheel width, you are going to want to choose a bs that will make the tire fit well in the wheelwell, providing clearance for turning and no rubbing on the body and suspension. Knowing what this is difficult to find. However, with a litte math, you can figure in my situation that my inner tire plane (the vertical of its sidewall) is 5.5" from the wheel mounting surface (wms) {10.5-7=3.5/2=1.75; 3.75+1.75}. If I had 12.5" wide tire, then it would be 6.5" from wms. Now, tire will stick out farther from the body with a bs to clear inside. This may be illegal in your state. To fix that, you can add wider aftermarket flares.

[dunklervogel]

Just wanted to thank everyone for the feedback..  I ended up getting a set of new wheels and tossed 32s on them with a 2" lift.   Although I haven't gotten to go wheeling yet I've had the new tires put to the test in some snow and ice and am pretty satisfied so far.  Highway performance dropped quite a bit though :(  I just barely kept 5th gear... have to downshift to maintain speed on any sort of incline.  Now just looking into some lower cost mods I can do myself to help that out a bit.  Don't want to regear if I can help it.. seems pretty pricey from what I've read.

[jagular7]

Just wanted to thank everyone for the feedback..  I ended up getting a set of new wheels and tossed 32s on them with a 2" lift.   Although I haven't gotten to go wheeling yet I've had the new tires put to the test in some snow and ice and am pretty satisfied so far.  Highway performance dropped quite a bit though :(  I just barely kept 5th gear... have to downshift to maintain speed on any sort of incline.  Now just looking into some lower cost mods I can do myself to help that out a bit.  Don't want to regear if I can help it.. seems pretty pricey from what I've read.

What you have basically done is learn the lesson of the larger tire. You have added a larger circumference (distance of a point on the tread to rotate 1 revolution) which in turns is an effective overdrive. To compensate, regearing is the option. Yes, you can add some engine mods, but you'll have to bring the torque and hp rpms a little lower or hp/torque higher at given rpms to make up for the lower overall rpm on highway. Free flowing exhaust, larger throttle body, and hotter ignition are some basic mods that are relatively bolt on. You can reduce the drag on the engine throughout the rpm range with an electric fan. You can look at lightening up your Jeep with removing the not-so-needed equipment. Or, last should I state, swap an engine with enough power-to-weight ratio. You could also look for swapping in already prepared mod'd axles from someone wanting to go bigger. That's an option.

[oldjeep]

I'm running 34x10.5 on 15x7 rims w/3.75" bs. The shallower bs provides the space necessary for a taller and wider tire in the wheelwell with enough spacing to keep off suspenion and body parts.

What gears are you running with the 34" tires?

[jagular7]

I'm running 34x10.5 on 15x7 rims w/3.75" bs. The shallower bs provides the space necessary for a taller and wider tire in the wheelwell with enough spacing to keep off suspenion and body parts.

What gears are you running with the 34" tires?

Deepest set of a stock TJ D30 which is 4.88s. I've got an 8.8 swapped in the back.  My next set of tires for this Jeep will be the Q78-15 TSLs. They are another 1+" taller (~36") and just as wide. I really can't locate any other tire with the 'Q78' size in a 15" rim size. There are several in the 16" rim size.