BurbMan wrote:
It should be noted that the door sticker says that the tires will carry the GVWR at 30 psi. You shouldn't need to inflate past that unless you are exceeding the GVWR, right?
Per the manual, this is the minimum air pressure required for the tire's load rating to match the axle's load rating. Per the TRA tables, additional air pressure would add margin to the tire's capacity (but not the axle's, of course).
mike-s wrote:
Use the manufacturer's recommendations, followed by the load tables. To figure it out independently, you need to travel a while under load, then quickly and accurately measure the tread temperature across the width, like the racers do.
You remind me that I do have a FLIR IR camera... The challenge will be in doing highway travelling, then finding a place to safely come to a stop and immediately hop out to shoot the tires before the heat dissipates or equalizes. Still, there might be enough benefit (and knowledge) to be gained here to try it.
lawrosa wrote:
I believe a 117 tire is rated @ 2833 lbs. Derate that 9% for P tires and you get 2578 lbs per tire.
And constant working load usually another 20% per the manufacturer's. So that equates to 2062 lbs per tire.
Whats your axle rate? 4000 lbs? Ahhhh.. Yup
To the OP. I would run at 40psi. Heat from the weight will be the issue. Higher pressure less heat.
Ive never ran the door tags psi in any vehicle I have ever owned. Always higher.
Wow, that's some nice math-ing you did there! Coincidentally, I set the pressures to 40psi all around to bring the trailer home, exactly for the reasons you describe.
owenssailor wrote:
When not towing I run 3 PSI above door sticker on all my vehicles. I feel handling is better as is tire wear.
This is what I normally do too (when not towing). I am also careful to do it in the early morning, so that the sun hasn't asymmetrically warmed the tires and the temperature is nominally low.
