Tow Vehicle Tire pressure

[callagp7552]

Hi All,
It's well documented to run your TT tires at their max cold PSI which I always do. I'm wondering if the recommended tire pressure in your truck changes with the amount of payload in the bed. The door sticker says the tires should be at 35psi while the max psi on the tires is 55. The rating indication on the sidewall of the tires says something to the effect of "the max load is XXX at 55psi" which suggests to me that in order for those tires to carry the maximum amount of weight they need to be filled higher than the generalized sticker says. Very curious to hear how others interpret this.

Thanks!

[traveldawg]

It might help if you list some details about your truck.

On mine the sticker says 60 psi in the front and 80 psi in the back.

80 psi is also the max psi for the weight rating of my tires.

I leave them at 80/60 all the time - loaded and unloaded.

The best thing to do is to get the inflation table for your tires and see what psi's are recommended for specific weights and go from there.

[CoChris]

Hi All,
It's well documented to run your TT tires at their max cold PSI which I always do. I'm wondering if the recommended tire pressure in your truck changes with the amount of payload in the bed. The door sticker says the tires should be at 35psi while the max psi on the tires is 55. The rating indication on the sidewall of the tires says something to the effect of "the max load is XXX at 55psi" which suggests to me that in order for those tires to carry the maximum amount of weight they need to be filled higher than the generalized sticker says. Very curious to hear how others interpret this.

Thanks!

If you are worried about weight capacity, remember that the tires are only part of "the system", an important part. Your TV will list the RAWR (Rear Axle Weight Rating) on the drivers door jamb. This is the limit of the rear tires, wheels, springs, axle, and chassis.

From your pressures (35 PSI) I am guessing you have P (passenger) tires. Going to LT tires (or just increasing your existing tire pressure) will give you more load capacity (as you have already figured out), but will also give you more stability in towing (less sidewall flex) but a stiffer ride.

Chris

[callagp7552]

Thanks for the replies guys. The truck is a F-150 with Hanook Dynapro AT2 275/55R20 tires that have a 113 load index. They are rated for 2535lb at 51psi (mistyped in my original post, sorry). I looked on Hanook's site but didn't find an inflation chart, perhaps because they aren't LT tires?

I guess all the years of driving "passenger" vehicles just created a mindless habit of blindly following the tire pressure sticker on the door. I understand the manufacturers of 1/2tons have to juggle comfort vs being a truck but why not have the sticker say psi depends on load. Or perhaps I'm just the last guy to come to this realization... Guess I'll start running them at 51 when towing and "air down" when daily driving if the ride is a bit too stiff.

[Cajun Couple]

Thanks for the replies guys. The truck is a F-150 with Hanook Dynapro AT2 275/55R20 tires that have a 113 load index. They are rated for 2535lb at 51psi (mistyped in my original post, sorry). I looked on Hanook's site but didn't find an inflation chart, perhaps because they aren't LT tires?

I guess all the years of driving "passenger" vehicles just created a mindless habit of blindly following the tire pressure sticker on the door. I understand the manufacturers of 1/2tons have to juggle comfort vs being a truck but why not have the sticker say psi depends on load. Or perhaps I'm just the last guy to come to this realization... Guess I'll start running them at 51 when towing and "air down" when daily driving if the ride is a bit too stiff.

Most 1/2 ton pickups come with P rated tires for a better ride and fuel economy. Tires also can be had in an XL rated version or LT tires that are offered on heavy payload or offroad versions. The 150 Ford tires I had were 275x55x20 Pirelli's rated at 44 psi max. I later put some LT 10 ply rated tires for heavier construction and the stiffer sidewalls when towing. I ran them at 40 to 45 psi to improve the ride for daily use. You're right about the inflation on the door jamb only being good for the stock tires. Change tires to an XL or LT rated one and those figures usually are voided.

[xrated]

Here is an example for my F350 Dually. First, max psi on the sidewall of the tire is 80 psi. Sticker on the driver side door post lists the front tires at 75 psi, and the rear (four tires) at 65 psi. If inflated to that cold pressure numbers listed on the sticker, the tire capacity total is more than the GVWR of the truck...14,000 lbs. So there is no reason to inflate them any higher than the door sticker numbers....they are already more tire capacity than the MAXIMUM weight that the truck should ever be....14,000 lbs.

[dragonfly]

Hi All,
It's well documented to run your TT tires at their max cold PSI which I always do. I'm wondering if the recommended tire pressure in your truck changes with the amount of payload in the bed. The door sticker says the tires should be at 35psi while the max psi on the tires is 55. The rating indication on the sidewall of the tires says something to the effect of "the max load is XXX at 55psi" which suggests to me that in order for those tires to carry the maximum amount of weight they need to be filled higher than the generalized sticker says. Very curious to hear how others interpret this.

Thanks!

I had the same question with my new F-450. The sticker on the door said 90lbs. on the front tires and 80 lbs. on the rear, the tires said 110lbs. . I then texted Second Chance and he gave me the advice that with original stock tires, always go by door sticker, otherwise your trailer is too heavy not only for your tires but the rest of your truck .
So this advice is assuming original stock tires.

[BobLandry]

The Internet is awash with attempts to turn tire pressure into rocket science. The door stickers are relative o the tires that came from the OEM. When you replace tires, and if they are not the same as original, that sticker is useless.
If you run the tires at the full cold pressure indicated on the tire, you get minimal rubber on the road, you get less sidewall flex, the tires run cooler, and thus are less prone to blowouts. There is no need to adjust the pressure to the load or trailer weight on the axles.

[ckreef]

On heavy duty trucks the door sticker lists the inflation rating to give you the tow capacity for what your truck is rated. In my case it's 60 front 80 rear but that is an extremely rough ride if I'm not towing.

After looking up the tire inflation chart and taking the truck across a CAT scale I can significantly lower the pressure when not towing. I have them inflated at 50 front and 45 rear when not towing and could even go another 5 psi less and still be within the spec of the tires for my unloaded weight.