LagerAle

Just installed a set of 31x10.5x15 Nokian Rotiiva's on my stock '94 reg cab 4x4 pickup's 6" rims. I've been incrementally lowering pressure and observing the wear/salt road grime pattern on my tread. I started at the door stickers suggestion of 26f/29r and noticed there is about 1 inch on either side of the tread that is not touching the ground (crowned). Ive lowered pressure down to 22f/22r and am getting close to good contact on the front, but still a little ways to go on the rear. Im guessing ill be at 20f and sub 20 on the rear before tire is properly contacting the ground. This seems very low to me. I realize I need lower pressures due to the larger volume tires and the narrow rim width, but 20psi just doesn't sound right...
Anybody else drive on the road with super low tire pressure?
Truck never gets above 60mph, and is never loaded down other than a couple hundred pounds of sand ill be putting in the bed for traction.

LagerAle

Bump.
Anybody?

SacRunner

I'm curious too.

I'm running 33x12.5s on a 15x8 rim and I'm down to 24 (maybe 26) psi and still have a little bit of crowning. Yes, I know I should step up to a 9" or 10" wide rim but I'm not too excited about that extra expense or extra width. I suppose I could drop down to 22 psi, but I don't know if I'm comfortable with that as the truck does still see a lot of highway miles and with the 3.4 swapped in can do well over 65 mph.

Sorry I couldn't help.

wyoming9

iTrader: (1)

With low tire pressure the thing one needs to worry about is excess heat.

I only run 235/75/15 tires 32 psi up front 45 psi in the rear

I am not much help

muddpigg

iTrader: (1)

I'm running 24psi with 15x8 rims and 35x12.5 tires. Minimal to know crowning. Thinking of dropping a couple psi with winter roads. But not much highway speeds on day to day. But even if you concerned about high speeds and lower PSI you can do test drives and check temperature at intervals to see if temperature is a problem, Google for steps and distances.

LagerAle

Great idea about checking pressure at intervals.

muddpigg

iTrader: (1)

I think I read article on 4crawlers site. He even mentioned measuring distance from lip of rim to ground on rear sides so you can compensate psi for weight of fuel tank. That guy is really thorough.