I've run my 32x11.50's on the stock 15x7 rims down to 8 PSI without any problems...I ran them like that for 3 days at pismo two weeks ago and even drove on the pavement like that to go get food and air up...Though it is a little sketchy driving on the street cause everytime you turn you feel like you're gonna roll a bead <img src="/forums/images/graemlins/lol.gif" alt="" /> But other than that I've run at 8 PSI without any problems

1999 Black TRD Prerunner X-Cab V6
3 Revtek Lift
32x11.50 BFG AT
8"x2.5" Sway Away remote resi. coilovers and Total Chaos upper arms sitting in the garage begging to be installed