What is the max safe cold tire pressure?

[CalandLinda]

It is the absences of knowledge that allows tire threads to linger on.

For original equipment tires the correct inflation pressures are found on the tire and load placard, federal certification label and in the vehicle owner’s manual. Inflation pressures above what has been recommended are optional, providing there are any to use. The maximum inflation pressure to gain the maximum load capacity for your tires is molded on the tire sidewall. Using pressures above the maximum number will not provide a load capacity above maximum for the tire.

Vehicle GAWRs are set by the vehicle manufacturer. They, along with the GVWR provide the maximum load for that vehicle. The rule for axle loads will differ for RV trailers. Somewhere in the building process, the vehicle manufacturer MUST include some load capacity reserves. For most tow vehicles that load capacity reserve will be provided with axles that exceed the manufacturers GAWR values. Exceeding the manufacturers GAWR values and loading to the axle manufacturer’s axle certifications will almost always put the vehicle in an overloaded condition.

[Jake101]

2011 F250 6.7 diesel 65 front 80 rear All the time

[BUBBA-NONNIE]

Originally Posted by Lee-CI

When I ran a ¾ ton TV I always ran 80 psi all the way around because that is what was stamped on the tire sidewalls for cold inflation pressures. I'm still running 80 psi cold pressures on the steer axle tires on the DRW dually.

The RVSEF folks aren't going to suggest dangerous information.

I run whatever is stamped on the tire.

[BuckandTeresa]

Originally Posted by mlh

When pulling my camper 80 pounds front and rear. No reason to run lower. The tires will run cooler and safer carry more weight.
Lynwood

Agreed— run my 2019 Ford F250 with max cold pressure 80 psi front and rear (Michelins) as stamped on the tire. Less flexing under load than with lower inflation, which means less heating while towing. I also installed wifi airbags when I bought the truck and trailer combo, I run them 65 psi loaded and 10 psi unloaded for comfort. They’re rock solid while pulling my 2019 3330RL.

I also agree with the manufacturer going for comfort on the door sticker.

[rpkittle1]

I don't know what the problem is? You look at the pressure/weight table the manufacturer publishes and follow their information. They knoe best. Weigh you truck and know what weight is on the tires. Add about 10% and run that pressure. The tire sidewall will tell you max pressure only. The door stricker is a general guide.

My weights say I should always have 65 psi in the front tires. I run 55 psi unloaded and 80 psi with the 5th wheel loades. My trailer weights say I could run 70 psi in all tires but I run 80 psi because of differing water loads. My trailer sidewalls say I can go to 110 psi but that would be like driving on steel wheels. I don't want to beat my trailer up.

My sin-in-law pulls heavy trailers all the time. He has found in the hot desert if he runs full tire pressure he has more blowouts.

[Theunz]

Running more pressure than the manufacturer recommends especially on the fronts can lead to a loss of traction particularly effecting steering. Especially dangerous when driving in rain or any other adverse conditions.

[rpkittle1]

As stated the F250 and the F350 are the same built truck including the tires. The F350 door sticker says to air the rear tires to 80 psi. How am I over inflating the tires?

[Foldbak]

Originally Posted by rpkittle1

As stated the F250 and the F350 are the same built truck including the tires. The F350 door sticker says to air the rear tires to 80 psi. How am I over inflating the tires?

My truck stickers say rear tires to be at 70 PSI. The tire says max PSI is 80. I run at 80 PSI when towing. The manufactures allow for expansion. Don't know the range but I'm sure their calculations are within normal ranges. I wouldn't be too concerned. Your TPMS will warn you if temp/pressure is exceeding nominal ranges. Assuming you have a TPMS. At 80 PSI running at 70 MPH with a tire temp of 135 I haven't seen the pressure raise more then 3 or 4 PSI.

[LERD]

Am I missing something here? My F350 dually placard says 75psi on the steer tires, and 65psi on the duals. I also have a 3231CK, and I'm towing beautifully. I'm pretty sure my max inflation is 80 psi. But I doubt I need it that high.

[KirkFess]

I worked for Freightliner for 18 years. Using that as my base of knowledge.
. In the original post, the reference to 65 pounds is the sticker in the door jamb. The 65 pounds on his truck is the recommended tire inflation pressure that the truck manufacturer gives. This rating is developed by the engineers to satisfy several things - safety, tire wear, and drivers comfort. The sidewall rating on the tire will be equal or higher than this number.

It is OK to exceed the number on the door jamb, it is never OK to exceed the rating on the sidewall.
I have a 02 ford f250 with E rated tires. I run the truck at the door jamb numbers when not towing or hauling heavily loaded. I run at the max rating on the tires when hooked to my Montana.

When I drop the camper at a campsite and run empty at the max pressures the comfort level is poor. It makes the suspension feel stiffer.

[jadatis]

Originally Posted by thomseninc

Michelin LTX AT2, 275-65R20, E rated. The door sticker says 65 psi, but I just looked at the “fine print” on the sidewall and it says max load of 3750 lb at 80 psi. I think my question is answered: run at 80. Thanks to everybody for helping. I feel bad about wasting everyone’s time!

Still would like to know if the 3600 lbs you gave, was weight on one wheel or on the axe, and if weighed empty or fully loaded.
If on axle and fully loaded( also the persons) 80 psi will give terrible bumping, and 41 psi only needed.

[masterdrago]

We have weighed 3x with the RVSEF guys. They always tell us to run tires for the load. But never exceed tire rating.

[thomseninc]

Originally Posted by jadatis

Still would like to know if the 3600 lbs you gave, was weight on one wheel or on the axe, and if weighed empty or fully loaded.
If on axle and fully loaded( also the persons) 80 psi will give terrible bumping, and 41 psi only needed.

One tire, fully loaded.

[jadatis]

Then full 80 psi is needed, and in my list given it gives 81 psi to have maximum reserve if heavyest side on the axle. So 80 psi a litle less reserve, but can do.

[CalandLinda]

Tire load inflation charts are collaborations between tire manufacturers and the Tire and Rim association (TRA). Their goal is to provide standardized load inflation charts for general use throughout the tire industry. The end product is not providing recommendations. They are simply providing a chart by designated tire size that is primarily used by vehicle builders when determining the settings of recommended cold inflation pressures for vehicles built under the guidance of FMVSS. Vehicles governed by FMCSA have a different set of tire rules and regulations and one is not applicable to the other.