Why do we air down our tires when going off road?
This is probably the main reason for airing down your tires.
A side effect of airing down is a smoother ride.
What tire pressure should I be using when airing down?
There are many opinions on this and depends on if your vehicle is equipped with bead locks or not. As a general rule of thumb and your vehicles do not have bead locks, you should not go any lower than 15 psi. My personal preference is 16 psi. If your vehicle is equipped with bead locks, you should shoot for 8 psi. I've heard some people going as low as 3 psi but I wouldn't recommend this.
Be cautious when airing down without bead locks. It is never fun to be caught popping a bead on the trail.
When should I air back up?
The most important thing about airing down is airing back up. So, when returning to the pavement, be sure to air your tires back up. Here's why. When traveling at high speeds along paved roads with lower psi, you run the risk of damaging your tires or worse, cause a blowout. You do not want to drive on paved roads driving on tires below the recommended factory psi.