I run 9 psi offroad. Not only do you need to account for terrain and sidewall stiffness you need to also consider wheel,tire width and tire size. I run a 10 wide wheel with 37x14-16 Iroks. I run mostly rocks and wooded trails in the Ozarks. I have plenty Tire height so I am not as concerned about over compressing the sidewalls and bottoming out the wheel.

So keep asking questions and plan to experiment on tire pressure until you find a value that suits you best.

always air down. who wants to get out in the mud and whatever else to air down at the obstacle when you can do it comfortably at the trailhead and not piss everybody else off when they have to wait for you. there's a reason everybody airs down all at the same time before heading out. plus, if you wait to do it on the trail and ur tires are full of mud and sand and everything, you have a greater risk of getting debris in your valve and having issues with leaks later on.

Airdown all the time you are not on road. It helps so much, before I never aired down and it just gives you a huge advantage.

Ok, so what if you have nitro instead of just air. I got it from the dealer that way and was told it would hold the pressure better and cause less wear. It's expensive to refill though. Any thoughts on air vs. nitro?

Nitrogen or air. take your pick, there is nothing difference between the two. There is like 78 %nitrogen in the air we breath. And all the thing they tell you about it is all a markiting gimmic. It does change pressure with heat and cold, it does leak.

Or you can just have one of these meet you at the trailhead. He can air you back up with N2.

http://www.bigeaglehydrovac.com/imag...trogenUnit.jpg

The advantages to running N2 in a Jeep are miniscule. The advantages to airing down at the trailhead and airing back up when you're done are huge. It's an easy choice.

And don't worry about just putting plain old air back into a tire that was filled with N2. As another poster said, the air we breathe is 78% nitrogen, so there's nothing to be concerned about.

We did some snow wheeling in northern Michigan this past weekend and none of us in the group initially aired down. After some very slow going in about 18-24" of snow we started to air down, what a night and day difference! I am running the stock Dueler's for now on my Sahara and initially aired down to 20psi and could tell a huge difference. After not being able to make it up a hill in the trail I aired down to 12psi and just walked right up the hill no problem. Our entire group learned that air pressure is key in snow!!

I disagree. Nitrogen does not expand and contract with heat like normal air does. The military has done a lot of research on this and that is why airplane tires are filled with nitro. That being said. The advantages of airing down a tire at the trail far out weigh the benefits of having nitro in your tires. I run nitro in my cars and regular air in my Jeep. If you get tires at costco they are filled with Nitro.

And I disagree with your statement :bleh:

Airplanes fly at like 35,000 feet. So it makes since that they have nitrogen. I don't think that my Jeep is ever going to go up that high. It's a gimmic and it's been shown that nitrogen in autos is not worth it.

http://www.straightdope.com/columns/...instead-of-air

Gauge quality...
 

I had a very similar result after losing the bead on 3 different BFG KM's, on two outings, thinking I was at 18psi- thanks to a shoddy gauge.