tire pressure on tow vehicle

To carry the load the tire is rated for, you need the max psi on the sidewall. If you are carrying less than that, adjust accordingly. P-metric tires are often filled to recommended pressure on door jamb sticker, but that is not for the max load, that is for comfort.

pasusan wrote:
Maximum tire pressure makes for a rougher ride. If I was you I would look in your owner's manual to find the correct pressure.

:R

On PASSENGER TIRES ON A TRUCK you will have virtually NO DIFFERENCE IN "RIDE COMFORT" whether you use 35 lb or full 42-50 lbs..

Towing difference is going to be night and day, 35 lbs is going to feel pretty darn squishy..

I NEVER ran a "P" tire on my heavy half at 35 lbs, empty I ran 45 lbs and loaded 50 lbs. The reason for that is running 50 lbs empty you have a better chance of wearing the centers off the tires..

I HAD a "heavy half" years ago.. I COULD NOT TELL THE DIFFERENCE IN RIDE.

Now if you are talking LT tires then driving on 35 lbs is considered a FLAT TIRE let alone 50 lbs..

My 2011 F-150 4x4 has P tires with a 35 lb. recommended pressure. The max rating on my tires is 44 psi. I do 38 front and 40 rear. Pulls just fine.

I think it offsets the 600 lbs. of tongue weight.

I do not know if the owners manual mentions adding pressure or not.

Bobbyg2013 wrote:
should I increase the rear tire pressure by 10 psi, on my truck's tires or leave at the suggested 35 psi that is shown on the sticker on the door jam?

What kind of tire?
What size?
What is the tire load range?
What is the weight of the trailer"
Go with the recommended PSI written on the side of the tire! Not the PSI on the inside of your vehicle, that assumes that the tires the truck came with are the same tires you have on your truck today.

A small truck then.. got it.

This sticker lists what the vehicle manufacturer recommends for tire pressures as a compromise of ride/handling and comfort. It also must be capable of handling the vehicle's load at GVWR.



Many people have experienced that a little higher pressure when the vehicle is closer to GVWR than unloaded provides a better ride and handling.

I generally avoid the tire pressure threads, but weighing in on P rated tires in general:
With the loaded weights of tow vehicles, running P rated tires can make for a less than desirable towing experience. If the OP has P rated tires and is not able or willing to upgrade them, then I personally would air up to the max sidewall pressure. In practically all other cases I air up based upon actual loads using the tire manufactures load table. IMHO, YMMV

My little truck ( Nissan Frontier ) has "P" tires. Normal inflation is 35 psi. Max on the sidewall is 44. I tried 44 on the rear while pulling the trailer and discovered that was over-inflated. Even loaded up, the outside rib of the tires was not touching the pavement.
I settled on 36 front and 38 rear in my case, and this seems to work well. The truck handles correctly, the tires wear evenly, and run cool even on hot days at highway speed all day.
Y'alls mileage, tires, pressures and experience may vary.

As for "squishy handling", the biggest change I noticed regarding that was removing the load range C ST tires from the trailer, replacing them with load range D LT tires. Much better towing experience.

EDIT: another improvement to the stability of the towing with this combo was replacing the OE shocks on the back of the truck. I installed monroe sensa-tracs at first, and they were an improvement. I have since replaced those with billstein 5100's, and those were another step up in improvement.

APT wrote:
This sticker lists what the vehicle manufacturer recommends for tire pressures as a compromise of ride/handling and comfort. It also must be capable of handling the vehicle's load at GVWR.



Many people have experienced that a little higher pressure when the vehicle is closer to GVWR than unloaded provides a better ride and handling.

Worth noting that the spare is filled to 80psi. Curious what the OP's spare tire is aired too?

I also experienced a squishy feeling when towing with the trucks suggested PSI. Once I aired up to the sidewall max, towing was night and day. Trailer tires, aired to the max, truck front and rear aired to the max. I keep it like that during the camping season, and then drop it back down to the truck recommended after the camping season is over, or if I am going on a trip without the camper. As for the rough ride, it's barely noticeable.