What pressure for LT tires

What are the wheels rated for? That is going to be your limiting factor

My truck came OEM with LT265/70R17-C and the door sticker calls for 36 psi.

I run ~42 front and ~48 rear.

donn0128 wrote:
What are the wheels rated for? That is going to be your limiting factor

They are on aftermarket alloy rims. Not sure their rating, I will have to check. Good point.

I run 60 rear and 45 front,E rated rear,C rated front

If you want to get technical, there are tables for what PSI to run for what weight you are carrying.

This is a real problem. Use the chart for weight/psi for that particular tire. You will need to use the actual axle weight divided by two.

Unless you do this you risk a rough ride and worn centers from overinflation.

My F350 with LRE tires calls out 80 psi on the door sticker which is fine for when I'm fully loaded to GAWR but when empty, I run at the psi that allows the tire treads to lay down. Much nicer ride and tire life.

Yes, this means adjusting your tire pressure when unloaded vs. loaded.

Weigh your truck loaded and unloaded use the inflation/weight chart for the tire you have and add 5psi to the chart. Done!

There are many inflation tables out there, but they share roughly the same inflation schedule dependent upon the load you plan on carrying. Your truck most likely came with the "P" series type of tire, which achieves max load capacity at 35 psi. Your LT tires will require more pressure to hit the same load range. So go find a tire maker's LT load table and select the load rating closest to what your OEM tires were. For my F-150 that I owned previously, my OEM tires were rated to 2,400 lbs per tire (P275/55R20). So I looked at the LT inflation matrix for Bridgestone (I actually bought goodyears, but the inflation tables I've seen are the same per tire size across all manufacturers I've looked into). In my case, that meant running 45psi to maintain the same load capacity.

Words of caution:

1) The tire load tables are MINIMUMS! (or maximums, depending on how you look at them). they are NOT recommendations. So if you use a table, be sure to use MORE pressure than indicated.

2) There is side to side weight variation that has to be taken into account if you weigh the entire axle as a unit. That would be on top of #1 above.

CapriRacer wrote:
Words of caution:

1) The tire load tables are MINIMUMS! (or maximums, depending on how you look at them). they are NOT recommendations. So if you use a table, be sure to use MORE pressure than indicated.

2) There is side to side weight variation that has to be taken into account if you weigh the entire axle as a unit. That would be on top of #1 above.

The tables tell you what the tire will carry at a specific weight. NOT minimum. NOT maximum. Just what it is.

Now the GY Tech person I talked to when I went from E to G on my RV said to weigh the axles and add 5psi to the chart.