Tire Pressure for Stock SE with 30x9.5s

[SSTJ]

I'm playing around with my air pressure these days, and will do some chalk tests. My theory is that with my Jeep being about as lightweight as they can get (97 SE 2.5L with minimal gear), and with larger-than-stock tires (30" KO2s), I could probably get away with something like 26psi for street driving.

I know there aren't many of us with Jeeps as lightweight as my stock SE, but I wonder what others have found.

 

[up on the mountain.]

I have the 4.0l stock. I am running the same size tires. what works for me is 28 psi for normal road conditions. if we get snow i drop down to 26 psi. for me that is the sweet spot.

 

[Jerry Bransford]

The chalk method is responsible for lots of underinflated tires. The chalk line will not be completely evenly worn away with properly inflated tires like our Jeeps run, primarily on the outer edges that aren't meant to come in contact with the road except when cornering more sharply than normal. Lowering the air pressure until that line shows wear across the entire tread will result in an underinflated tire that will run hotter.

There is a sticker on the driver's side door jam that gives the correct air pressure for 30x9.50 tires as one of the optional factory tires.

 

[WallyWest]

I run that size and have them at 28psi. I did 26 as well and felt no difference. They were at 35 when I bought it and it rode like crap.

Mine is a stock Sport with the 4.0.

 

[SSTJ]

The chalk method is responsible for lots of underinflated tires. The chalk line will not be completely evenly worn away with properly inflated tires like our Jeeps run, primarily on the outer edges that aren't meant to come in contact with the road except when cornering more sharply than normal. Lowering the air pressure until that line shows wear across the entire tread will result in an underinflated tire that will run hotter.

There is a sticker on the driver's side door jam that gives the correct air pressure for 30x9.50 tires as one of the optional factory tires.

Thanks Jerry, that’s very good to know.

It also makes me wonder: do those of you with heavier 4.0s have a different factory recommendation for 30” tires? In the door jam, like Jerry said. Mine, an SE, recommends 29psi.

 

[Uncaged]

I have the 4.0 in my Sahara with 30x9.50 tires stock, the sticker recommends 29 psi.

 

[SSTJ]

I have the 4.0 in my Sahara with 30x9.50 tires stock, the sticker recommends 29 psi.

Thanks. That makes me wonder if I can get away with a little less, with my SE. But Jerry’s advice will keep me from doing anything too stupid.

 

[TJim]

I run my 31x10.5r15 at 29 PSI.
I have a very lightweight 2.4L SE too. It rides well. I have those tires for less than a month. I might try different pressures in the future but I think it rides well atm