Aired down to 14 psi with 1 tire at 13 psi with 315/70/17 ko2's load c on a 17×8.5 wheel on rocky terrain at an offroad park. Had folks comment as to how well they flexed and widened...said the flex was a good bit more than others with 35" toyo M/T and bfg km2's. Had no issues running them for 4 hrs..
I aired down to 5 psi on a recent snow run without a problem, though I was very careful. I started at 10 psi but the Jeep kept braking through the top layer of ice/snow. @JIMBOX is correct in that you lose significant ground clearance. My Jeep looked like a low rider at the time!
I could see dropping down to 5 in soft sand but not for rocky sections. I haven’t had a chance to do any rock crawling yet, but I expect that I’ll shoot for somewhere between 12 and15 psi.
I’m running 315/70R17 C load rated KO2s on stock rims.
12 psi on stock rims and 315/70/17 Patagonia’s. You might want to check out the method 701’s. I got a set and I can air down to 8 psi without breaking a bead, they are not bead locks but a good compromise because they have a special beadLip.
I aired down to 8 psi on my LJ with stock 16" size wheels and tires (Bridgestone Revo 2). But all on sand. The terrain makes a difference too. I'm planning 11 to 15 psi on firm rock terrain on my stock JL Rubicon. & KO 2s
Always a good idea to ask the locals at the trail too. I will do that to confirm my plan on my next new trail.
Weight at the axle divided by the max load stated on the tire multiplied by two (since there are two tires on each axle). Add 20 percent to that number for a safety margin. Now multiply that times the max load pressure stated on your tire. This number gives you the street pressure for your tire. Divide that by 3 for the lowest minimum off-road pressure for your rig on these tires.
Weight at axle
________________ = A
Max tire load x 2
A x 1.2 = B
B x Max load psi = C (your street pressure)
35% of C (or C x 0.35) = your lowest minimum off-road pressure