Lift & tire size

[tjrubicon]

I finally got a lift kit ordered It's a 4 inch Rough Country, comes with just about everything except upper control arms. Now my question is this, what should I do for tires? I haven't decided if I want to go with 15X8 33-12.5s or if I want to keep my stock 16x8s and go with some 285X75R16s :confused: . If ya want to get a technical and stuff, 32-11.5s are 31"s tall, the same as the 245X75R16s, just wider. Therefore, I'm not sure if I want to go with an actual 33" tire or a 33-12.5 thats only 32"s tall but wider. I would like to run MT/Rs, cause them tires ROCK!!! Thanks for your help.

[goodtimes]

Overall installed height of any tire will differ from what any of the advertized measuments say. Wheel width and air pressure play a big role, as does the amount of wear. For example, the 245/75R16's on my jeep are "supposed" to be 30.5" tall (according to the calculator on 4lo.com), but when you measure them....try 29" on for size. The 285/75R16's sitting in the garage (waiting for the lift) are "supposed" to be 32.8" tall....they are right at 32", uninstalled.

So, if I were to figure the installed height of the 245 with full tread (19/32), the height would be 29.6875". That is reached by taking the current installed height of 29", minus the tread depth (.250 x 2), plus the original tread depth (.59375 x 2).

If I use the same formula for the 285's, I end up with 32.1875" (uninstalled).

So, what does it all mean? Not much, other than MT/R's run short....just like most brands of tires. I guess I'm saying that you shouldn't count on the advertized size of any tire....

and yes, MT/R's rock!

[tjrubicon]

I see your point. I measured my stock spare (245) with my girlfriends 32"spare. No load on them, fully aired and got 31" (or realitively close) with the good ole tape measure. I know that's not completely accurate, but it was something to do when I was bored.....I believe Goodyear should give us Jeepers an 90% discount on MT/Rs, those things cost some money!!

[goodtimes]

Yes they do. But they last so much longer than the BFG's do (I have just over 36K on mine, with 42% tread left), and they stick to the rocks better, and the sidewalls are extremely tough compared to the french tires (BFG).

[seapahn]

My new 35x12.5 MTRs on 15x8 wheels measure about 34" in diameter.

[nagal]

BFG is a French company? I guess I will cross that brand of my list

[tarzan]

i worked in the tire indust. for 5 years and the size depends on the manufacture most tires are not the same as you can see but there are tires out there that are what they say they are just keep lookin. toyo just came out with a bad tire we just use in the rubicon it worked well it only comes in a 35 but they will have outer sizes soon.