Until you get below 15 psi, you're not really airing down for offroading. You can safely air down to 11-12 psi. But part of that depends on your wheel width... you can safely air down to lower air pressures before it may unseat with a 15x8 wheel than you can with a 15x10 wheel.
Even before I got my beadlock wheels I would air my 35x12.50 tires on 15x8 wheels down to 7-8 psi for tougher trails & they never unseated.
__________________ When you have a choice, buy American.
Like Jerry, I am also running 35x12.50 tires on 15x8 non-beadlock wheels. I regularly air down to 12 psi front, 10 psi rear and have no issues whatsoever off road. I leave a couple extra pounds up front since (in my mind, anyway) a tire that steers is more likely to unseat... though I'm pretty confident I could drop another two pounds without worry.
__________________ Dempsey Bowling
My fleet: 91 Miata, 98 Wrangler Sport, 06 Mustang GT, 01 Suburban 8.1L, 14 Forte EX
Jeep mods: 4" longarm + 1" BL, 35" KM2s, 4.56s with dual ARBs... and lots of scratched armor
Not knowing your exact specs, I'm running similar. 285/70x17 (33x11.5) tires on 8" wide rims. I had been airing down to 12 psi. I recently started going down to 10 with noticeable improvements. My tires were barely squatting at 12. Never burped any air or had any issues.
Thanks for the great responses.. I will look at the width of my 17" rims and get the exact tire size tonight and post up.. however, it looks like I am heading to 10 lbs for this excursion.
on a related note, my buddy Mike and I installed the holders for the CO2 tank last night in the tub of the Jeep. They should work well..
Aired down to 11 psi and what a difference. Thank you all for the advice. As an aside, used my new CO2 setup to air back up. All Incan say is W O W. this is the setup for the truly impatient. Took maybe a minute per wheel.