I'm running 14 psi in 30x10xr-14 quadboss QBT846 tires. I have portal hubs and a bunch of extras. They are still squatting a bit and work great. I would rather have a little too much air then not enough. I don't want to break a rim or pop a bead. The old off road saying is, it's a lot easier to let air out if you get stuck and need to then to put air in (especially if the bead is popped or the rim is busted). Most guy go too low, and in most cases it really doesn't help much, if any at all. Just a little squat is good.