I have a set of 4 Maxxis bighorns, what I'm wondering is as anyone be able to run this under 15 psi? they're 31x10.50x15 wit a 6 ply rating. I don't want to pop the tire if I go to low. So do you guys think it'd also be safe to even go that low for mudding were I might hit sharp sticks/ and or rocks? Any input is helpful