Specifications

Looks like 50 PSI would be a good choice for the radial tire in the chart below from Michelin.
Bumping by 5 – 10 PSI will get you to 60 PSI for the same reasons noted above. Note that this
chart says “per position”. That means the left rear, right rear, left front or right front. That also
means that the capacity listed for the rear duals is for a PAIR of tires.
These Radial tires are maximum rated
for 3,042 lbs. each – when inflated to 80 PSI. That
doesn't mean you can put 80 PSI in each tire and increase the capacity for the axle. Nor should
you just inflate to the max without a reason. Overinflation is almost as bad as underinflation for
handling. All you are really doing is adding too much air, making the ride harder, and messing
up the handling. Do it right. There is an optimum pressure for your tires, giving the highest
possible grip. Any pressure over this will bulge the tread in the center causing a loss of traction
because there is less rubber in contact with the road, and any pressure under this will cause
excess distortion of the tire and a loss of traction.
LT235/85R16 LRE
PSI 35404550556065707580
Lbs per
position-
Single
1700 1870 2030 2205 2335 2485 2623 2765 2905 3042
Lbs per
position-
Duals
3090 3400 3690 4015 4250 4520 4765 5030 5290 5556
One more thing. Use the size tire recommended by the manufacturer. This is especially
important to ensure the tires match the rim's capacity, fit in the wheel well, and in the case of
duals, are properly spaced from each other. If the duals touch sidewalls, they won't last and are
a hazard. (If you do decide on bigger or wider tires, work with a pro. Substituting LT235/85R16
tires in place of 7.50-16 tires is probably not going to work in the duals position without
changing rims too – they would be too close together.) By the way, a bent rim can cause
problems, but should be caught when you have the tires balanced.
Current load and inflation information for popular auto tire sizes may be obtained from your
local tire dealer, or tables may be obtained free by sending a stamped, self-addressed business-
size envelope to "Tables," Tire Industry Safety Council, Box 1801, Washington, D.C. 20013. See
the Appendices in this document for an extract from the P Chassis manual with inflation info.
The chart for tire inflation in one of the appendices is from the service manual and is not
current (it was published in 1995). It is provided as a general guideline – but exact inflation
pressures should be obtained from your tire manufacturer for your brand and model of tire.
Don't forget to torque the wheels correctly:
http://users.sisna.com/cebula/P-Chassis-AlignmentProcess.pdf 13 Version 0.7 –Sep 14, 2005