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Discussion Starter · #1 ·
I've recently put some 11/32's on 8" rims and noticed they were riding on the center of the tread. How low should I run the tire pressure and still be okay at highway speed.
Thanks

 
G

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There is no set answer, it depends on your Jeep. You can just let a little out at a time and fine tune it, or use some chalk and a flat piece of pavement to figure how much pressure you need.
Chalk a line across the width of the tire and drive it forward, if there is still chalk on the tire you need to remove some air.......

_____________________
John
95.5 YJ with "stuff"
http://SonsofThunder4x4.com
 
G

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My 33x12.5x15 on 15x8 rims are at 16-18 lbs. I should take a little more out but they ride good and are pretty even right now. BTW, the weight of your vehicle makes a large difference. I only have a 4-banger so mine's pretty light.

Nick Hagen
1995 Wrangler
33" Mud Tires and a four banger
 
G

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I have an 86 CJ7 with 32X11.5 BFG MT's and run 27psi on the street to get even wear. I've run sustained freeway speeds for hours like
this with no problems.

Gary
 
G

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You can lower the tire pressure down, but you are still going to have improper wear on your tire(like outer edges not making contact with road surface). You can go with wider rims like 9 or 10" rim and it should allow your tire to have full contact with the road surface. This is what I experienced in the past, if you put too much tire pressure(like 40 psi) your ride will be very harsh(your suspension is taking most of the impact). If you have 20 psi tire pressure on all tires, your ride is most likely be soft. But, your tires' side wall are subject to get damage more easily.

Good Luck,

[email protected]
 
G

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there is actually a formula to figure out what pressure you should run. let me see if i can relate it to you.
Each tire has printed on it a MAX LOAD rating, for my 31/10.50's it is 2250lbs at 50psi cold. so that means that each tire can hold 2250lbs of vehicle at 50psi. unless your truck weighs 9000lbs you dont need 50psi. lets assume that my jeep weighs 4000lbs (????) and we will say that thats 1000lbs per tire. so you set up an equation that looks like this:
2250 1000
---- = ----
50 x
you cross multiply then devide: 50x1000 devided by 2250= 22.2psi per tire! but whait....THERES MORE!!! you also have to take into account that the front end weighs more and adjust your calculations accordingly. mayby 1200lbs per tire in front and only 800 lbs per in back or however your weight distribution works out.
If you know the exact weight of your vehicle at each tire, you can devide the MAX LOAD by the psi at the MAX LOAD and figure out how many lbs of vehicle each pound of pressure holds. ex: 2250 devided by 50= 45. every pound of pressure you put in your tire holds 45 pounds of jeep! (for my BFG's)then devide the weight of the vehicle on that wheel by 45 and you get your pressure!
also this will be the minimum tire pressure you can run at maximum tire rating speed (usually 100mph or more). thats why you can get away with 7psi off road. I hope i helped, its been a while since i went to tire school and learned about all this (we got a bonus every time we went to these stupid training seminars when i sold cars, i also know the intricate details of side body stamping and four sensor-three channel ABS!)




 
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