Which PSI rating to go by

[ACZL]

Okay, so now I'm confused. When airing up tires on trucks for towing, do ya go by the sidewall PSI or door data label? I always thought the door label was lower and yet sidewall says max "X" pounds at "X" PSI. :h

[Grit_dog]

Atlee wrote:
That's what I figured. The yellow sticker has inflation pounds as the truck is sold. The manufacturer doesn't know how anyone will load the truck. Also, manufacturers also want the "softest" ride possible.

All that said, as per my other post in this thread, I inflate to the sticker, 55# front, 60# rear on OEM LRE tires. I do not adjust when I'm towing my 6500# GVWR trailer. Truck doesn't squat, and the tires side walls do not sag any.

Bobbo wrote:
The tire pressure is set by the weight they are supporting. The door jamb numbers are from that chart using the curb weight of the truck. If you don't add much more weight when towing, that number is fine. If you add a considerable amount of weight, you need to weigh the truck to get an accurate weight, then use the weight tables from the tire manufacturer to determine the proper psi for the tires at that weight.

Not true. These "stickers" generally comply with gvw or in the case of 2500s now they spec basically max pressure in back for the worst ride possible when empty.

[Atlee]

That's what I figured. The yellow sticker has inflation pounds as the truck is sold. The manufacturer doesn't know how anyone will load the truck. Also, manufacturers also want the "softest" ride possible.

All that said, as per my other post in this thread, I inflate to the sticker, 55# front, 60# rear on OEM LRE tires. I do not adjust when I'm towing my 6500# GVWR trailer. Truck doesn't squat, and the tires side walls do not sag any.

Bobbo wrote:
The tire pressure is set by the weight they are supporting. The door jamb numbers are from that chart using the curb weight of the truck. If you don't add much more weight when towing, that number is fine. If you add a considerable amount of weight, you need to weigh the truck to get an accurate weight, then use the weight tables from the tire manufacturer to determine the proper psi for the tires at that weight.

[bucky]

The direction of rotation is a great idea on the fronts. Sadly I no longer have free access to a full shop. Retirement has it's good and bad points.

[Cummins12V98]

"And just for the record, RWD vehicles (and I don't know of any trucks towing a trailer that aren't!) wear the shoulders on the front tires and the centers on the rears. That's just the way it works and I would advise against adjusting the pressure to try to change that."


Well I guess I wasted my time running pressures based on LOAD. This set of MS2's have 40K on them rotating the fronts side to side with rotation staying the same and rears never moving.

HMMMMM

[JIMNLIN]

Dave H M wrote:
:h something must be wrong with my tow vehicle cus it don't work that way.

Nor does any of the three different trucks I own (1/2 ton...3/4 ton....one ton DRW).
One doesn't have a yellow tire placard sticker....gosh what did we do before the sticker.
All three truck are operated empty and at times are carrying max axle loads.
I regulate tire pressures for a empty truck and loaded and I also rotate every 6k-8k miles. That way I get a flat across the tread wear and 50k-80k miles of service.

I have a air compressor and its easy for me to regulate any tires pressures in just a couple of mins.

[Bobbo]

The tire pressure is set by the weight they are supporting. The door jamb numbers are from that chart using the curb weight of the truck. If you don't add much more weight when towing, that number is fine. If you add a considerable amount of weight, you need to weigh the truck to get an accurate weight, then use the weight tables from the tire manufacturer to determine the proper psi for the tires at that weight.

[Dave_H_M]

:h something must be wrong with my tow vehicle cus it don't work that way.

[AlmostAnOldGuy]

Yellow sticker is the manufacturers recommendation based on the rated weights for the axles / overall vehicle weight when loaded. That should correlate with the chart Burbman posted. When you are unloaded and have less weight you can reduce the psi. Running at the correct psi provides better ride comfort and tire performance (grip, braking). Now that I have that TPMS the darn thing glows on my dash when I air down to where I want to be so end up running higher psi than I like when unloaded.

Good luck,
Stu

[MFL]

As always, CapriRacer makes sense, and is giving a good reason to rotate tires, to get optimum mileage. I always error on the side of SLIGHT over inflation, rather than under.

Jerry

[CapriRacer]

And just to clear up a point.

A bit of overinflation doesn't have a great effect on tire wear. There are other things that have a much greater effect - like wheel position, alignment, and aggressive driving.

So over-inflating the tires a little (say 5 psi) on a tow truck isn't going to ruin a set of tires.

And just for the record, RWD vehicles (and I don't know of any trucks towing a trailer that aren't!) wear the shoulders on the front tires and the centers on the rears. That's just the way it works and I would advise against adjusting the pressure to try to change that.

[Atlee]

The yellow sticker on the door jam of my truck says 55 front, and 60 rear. That's what I use, towing or not.

I have LT245/75R17 LRE OEM tires.

[Grit_dog]

Neither. Air tires up or down for the load they’ll see and do not go over the sidewall max or less than safe for popping a bead.
I’ll run 80 psi max tires anywhere from 20-80psi depending on what I’m doing with the vehicle at the time.

[ktmrfs]

door jam number at the minimum. you may find a slightly higher pressure gives you better handling, usually at the expense of ride.

The Max pressure is the max the tire is rated for at it's max load. So unless your going to have that load on the tires, your likely over inflating.

[Cummins12V98]

downtheroad wrote:
The tires are what you put the air in, not the door jam....I go with what is stamped on the tires..

(are they the original tires or replacements?)

Please explain why???