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Upgraded tire pressure question

R

rjake4

NAXJA Forum User
Location
Lawson, MO
ry%3D480



I've upgraded tires just a smidge with a small lift (30 x 9.5 with a 2" lift). I know that the number inside the door overrides the number on the tire as proper pressure. On the stock tire the difference is 33 PSI on the door and 35 PSI on the tire. No big difference. My new tires (Kuhmo Road Venture SATs) say 50 PSI. Big difference. What should be my on road pressure? This is a daily driver, with occasional off road excursions. Thanks.
 
Jeep didnt make your tires Kuhmo did, run what the tires say, and the 50 psi is probably max tire pressure not what you should be running in them, they will be really stiff, if 35 felt good on your last tires then run 35 on these and if they feel too soft add more air pressure

seth
 
my truck tires say 80 but i run 50 unless im towing, if i run 80 unloaded then its kinda a bumpy ride
 
The label on the door is correct for your jeep. you could go to a higher pressure but you will get a rougher ride and very likely uneven tire wear (wear out the center faster) I run these tires at the 33psi w/o problems.

I have these same tires only in P235/75/15. Welcome to the SAT tire club, no one seems to run these! On here or other wise. I bought them b/c 99.9% of my driving is street, but i wanted a tougher tire than a street tire to hold up on the mountain woods roads i take while hunting. For this they are perfect, i'm quite happy with mine. I'm very interested in what you have to say about them.
 
Door label is correct tire pressure for stock tires based upon the Jeep engineers' calculations.

Tire label is max tire pressure based upon the tire manufacturers' calculations.

Unfortunately, there is no chart showing the correct tire pressure for your particular combination. If you search this site, you'll discover a few ways of determining the proper pressure. Probably the most popular method is the chalk method. Abbreviated version: Mark a chalk line across the tread of your tire. Drive straight ahead for a bit. Check the chalk mark to see if it has worn off evenly. Adjust tire pressure accordingly...
 
Yeah, those are the stock tire size recommended pressure and the max tire pressure. You don't want to be running either. Follow fyrfytr's description of the chalk method for one set of tires (I would go with the front set, you want those wearing evenly for sure) then measure their exact rolling diameter from center of hub to flat ground and fill the rear tires till they're the same rolling diameter. This should give you approx. the same pattern on the rear and will result in smoother shifting in and out of 4wd.

50psi will probably knock the fillings out of your teeth, I end up running my 32s (and probably the 33s soon) at 25-27psi.
 
The way I like to use is to check you tire pressures go for a long drive and check your tire pressure as soon as you stop so the tires are still warm. You should be up 3-5 lbs.
 
Banditt007 said:
The label on the door is correct for your jeep. you could go to a higher pressure but you will get a rougher ride and very likely uneven tire wear (wear out the center faster) I run these tires at the 33psi w/o problems.

I have these same tires only in P235/75/15. Welcome to the SAT tire club, no one seems to run these! On here or other wise. I bought them b/c 99.9% of my driving is street, but i wanted a tougher tire than a street tire to hold up on the mountain woods roads i take while hunting. For this they are perfect, i'm quite happy with mine. I'm very interested in what you have to say about them.
Click to expand...

I love them so far. They look great, have an aggressive tread for what I need and are fairly inexpensive (tirerack.com). Put many a road mile, and a few offroad ones, and I'd buy them again. A friend of mine turned me on to them, so add another to the club.
 
quick and dirty way, get some greese chalk, draw a line across youir tread, drive 10 yards straight line, if center of chalk worn off, air is too high, if edges worn off too low.
 
Wet the ground in the street. Fill the tires to 50 PSI. Let pressure out in small increments until when you drive over the wet ground the tire gets wet across the whole tread (assuming the alignment is right). Go about 2-3 PSI less than that and that should do you just fine.
 
Wet the ground in the street. Fill the tires to 50 PSI. Let pressure out in small increments until when you drive over the wet ground the tire gets wet across the whole tread (assuming the alignment is right). Go about 2-3 PSI less than that and that should do you just fine.
 
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