I would run 12.5s on an 15x7 rim before I would ever run them on a 15x12. You will be running a great risk of popping beads if you air down the tires any fairly decent amount. 8" wide rims are the best setup for 12.5s. 10" wide rims are decent, but then again you start running into bead popping issues when airing down. If you don't wheel the truck and just drive it on the road then you probably wouldn't have any issues.

The first time you rub your tire/rims up against a rut or a rock and the bead pops off, you will have wished you went with a narrower rim for the 12.5s.

Last edited by DRaider90; 01/06/10 02:09 AM.
88 Raider(Red):160k-Reman'd 2.6-5spd-Weber-SW Hubs-34x9.5 TSL-OffRd Pkg-1"Tbar-2"BL-CB
88 Raider(Silver):No 2.6/Bad KM145 Parts/Project
88 Montero(Brown):No 2.6,4.88s Parts/Project

[b]4X4 STICKERS,SHIRTS,ETC:
4WD Stickers AT COST.[b]