I've installed 37s on my JK and I'm curious what other people are running their PSI at. I haven't checked mine yet, I basically drove it home and parked it. And then, left for work. I noticed on the Newbie questions - its states to run it at 24-26 PSI. Seems low to me, but what is your experience? What are you airing down to on the trail? These are my firsts 37s, so your input is much appreciated!

 

You'll probably find answers all over the place. A couple of things will have a lot of bearing on where people have ended up. Sidewall strength, vehicle weight, tire profile and wheel width. The main thing you want to address is left to right uniformity of the contact patch.

The best way to check for uniformity of the contact patch is the chalk test. Simply draw a chalk line across the width of the tire tread drive 30-50 feet and then check what's left of the chalk line. If there is chalk remaining by the sidewalls you are over inflated. If there is chalk remaining in the center section you are under inflated. Also check your front and rear tires separately as they might have two different inflation rates.

I'm currently running 35s on 8.75x17" wheels. I'll run 30-32 psi, season dependent. I do the chalk test on the rear wheels, and then change the front tire pressure to a point where I don't have any understeer and a slight bit of oversteer or the ass end feeling a bit loose. It can be somewhat of a fine line and for me with a 2 door being too loose can really get the heart rate up. It will also handle quite differently if I have a bunch of gear in back.

So real quick on the front tires,

Understeer Correction (Pushing or plowing with front tires sliding first)

Raise Front Tire Pressure

Oversteer Correction (Loose with front tires sliding first)

Lower Front Tire Pressure

 

Interesting - I will need to try that and see what pressure I end up with.