Tire Pressure

[Jamie]

I took my Jeep in to a tire shop this week to have a screw removed from my front passenger tire. I am running 35" Cooper Discovery, E load on 17" rims. The owner of the shop told me under no circumstances should I be running below 40#'s pressure. When I ran Yankee Hill I was at about 25#'s and had been driving on that for 2 months. He told me I should not air down at all. Everything I have read, and everyone I have talked to disagree with his advice. He currently has me at 42#'s, and it is a rough ride. I have a 2010 JK with a 3" lift. I apologize if I have used the wrong terminology, this is all very new to me. Any advice is appreciated.

[Java]

Airing down offroad is SOP. It makes the ride much smoother, you grip stuff better and better puncture resistance. The store guy probably doesn't go offroad.


https://www.youtube.com/watch?v=9Kz8mmLkeks

[Jamie]

He told me my sidewalls would breakdown. He also said I would need to purchase floational tires if I wanted to air down, then said my current wheels would not support a flotational tire. I googled flotational tires are came up with no results, besides agricultural tires.

[FINOCJ]

Please air down for off road travel - everything will work better. On road air pressure is a bit up to you. Lighter vehicles on stiff sidewall tires might not run as much pressure as heavier vehicles on soft sidewall tires.

[ExplorerTom]

The tire guy is an idiot.

Air down offroad. I've seen stuck vehicles free themselves just by airing down.

[Jamie]

Well quit honestly James I have known this guy for years. Never had a reason to not believe him. But I trust your advice far and above his. I have done due diligence in researching this and have found nothing to support his stance. I just wanted to run this by everyone to learn as much as possible.

[Jamie]

Also James, had you been driving my rig on Yankee would you have aired down below 25#'s?

[Java]

https://www.exploroz.com/forum/73559/1998-death-at-halligans-bay---caroline-grossmueller

[GPP33]

He may be a tire guy but knows not of what he speaks. Stock tires should be aired per the door sticker (only when on road, always air down off road). Your rig didn't come with 35's though so toss that number out. Off road I go to about 10psi. Better grip on rocks, smoother ride on bumpy dirt. On road I run about 25. You need to figure out what PSI works for your tires on your truck. Draw a line across the tread with chalk, dive it 10 or 20 feet and see if the chalk has worn off more in the center or outside edges or if it's evenly worn. Worn more on in the center=less air, more on the outside edges=more air, even=perfect (more on one side than the other =get an alignment). After you get it set if it feels squishy add a little until it feels right.

Load range E sounds a bit overkill for a jeep though. I run that same size and load rating tire on by 3500 Cummins.

[cornpone99]

I have 16" rims 33" tires
I like 14psi off road
35psi fron 30psi rear when driving to moab
30psi front 25psi rear going to local spots

[Brian]

He's not a liar, he's just regurgitating the "company line." Under most day-to-day use his advice is good. But honestly, what others have stated is good advice. Go with your unique requirements and have fun!

[Jamie]

This group is so great! Thank you all for your time to clarify this for me!

[The StRanger]

I run 32 to 35 on the road but trail at about 10 to 12 psi.
Just ask the wife. We started MSV at 35 and damn need rattled out teeth out.
Stopped and dropped to 12 and rest of the trail was like ridding on marshmellows...

[redneck23ms]

another reason your ride is harsh is the fact that your tires are load range E. the sidewalls on those tires are really stiff. they are designed for 3/4-1ton trucks not jeeps.

[Heather]

I've always run about 12 psi on the trail, 32 front, 30 back off the trail. More comfy, more even wear that way.

[Spieg]

There is an old method I use to determine best inflation pressure. In short, mark a line with chalk across the tire tread. Then drive straight ahead a short distance and then look at the chalk remaining on the tread. If it is more worn off in the center then the tire is over inflated. If it is more worn on the edges, then it is under inflated.

[Swank1975]

I run my BFG KO2 at around 40PSI on road on my 1992 Range Rover Classic and they do pretty well there. Offroad I drop down to about 20psi.