As a point of reference, I have the same tires on the JK as my 4 door Diesel Silverado (285 75R16 Load Range D), when I tow my RV that weights 11,800 # loaded, I run 65 in the front and rear. Without the trailer and the tires at 65psi, it rides horrible - and the truck weighs 7400 # empty. A JK with the tires pumped to 65psi must allow you to read the year on a penny when you run over it.

 

BTW nothing new but i run my 33's rarely over 25-30 psi....hope she rides better 4 ya

 

oh ya, absolutely, theres nothing exact about it, the math just helps to give you some peace of mind, great starting point for you to figure out from there...but for a tire shop to have inflated them to 65psi and they do this for a living

 

Well, I am sure the guy just read it on the side of the tire and pumped it up. It did ride like HORRIBLE, last night I aired them down to 50psi and it rides better. Once it stops raining, I will air them down to 30. I suspect the ride will improve dramatically.

 

run 35psi at Max as others have said 30 should be almost perfect

 

34 is the magic number
There's someone on here who swears going from 35 to 34 makes a big difference... of course that would depend on the tire etc, but it'd probably be worth testing out several different tire pressures to see what suits you best.

 

You will be amazed at how you can feel the difference between as little as 2-3 psi. My 32's I ran at 30-32 psi. My 33's I ran at 28-29 psi. My 35's I run at 24-26 psi. This was all determined from chalk test and then rounding up or down based on comfort and feel. Keep in mind that a cold tire can increase 2-3 and sometimes as much as 4 psi after it heats up while driving. I would suggest doing the chalk test after you have been running around town for a little while. That will give you the most accurate feedback. I can actually feel my tires being a little UNDER inflated as I am leaving the neighborhood, but it is all good within a few miles. Likewise, I might air up a couple psi for a road trip to improve mileage, and I can def tell the tires heat up and the psi increases even more after running the highway at 75 mph for a while.

 

I am running 26# in my 35's, got to that piont using the chalk line method. It rides and handles better and the wear is even all the way across after 20,000 miles. The idiots at the tire store had mine at 60# when I bought them which made it near impossible to drive, needless to say after a couple miles I stopped and dropped them to 30# then adjusted later. I believe the tire store DUH's read the maximim pressure on the sidewall so that's what they put in them.

 

But what about the hated tire pressure signal, when I running at 24 psi on my 34"s that hated signal coming on.

 

That's the nice thing about an '07, no TPMS involved.