I've always increased the tire pressure in my trucks if I was towing or hauling very heavy loads. All the vehicles in the motor pool of the electric Utility I worked for had the tire pressure stenciled on the fender over each wheel and that number was the tires max load rating pressure. Didn't matter if it was a 1/2 ton pickup, line truck or bucket truck. Years ago I read or was told the recommended tire pressure the manufacturer places on a vehicle is a compromise between load capacity and ride comfort.

I bought a new F-250 recently and decided I'd contact the tire company and ask them about it. The tires on my truck are Toyo's. Ford recommends 65 psi front and rear. The tires max load capacity is at 80 psi. I asked for a specific pressure recommendation for my truck when towing a 5th wheel that has a 2,700 pound pin weight.
Here is the response to my question:

The pressure recommendation is as noted on your driver side door placard at 65 PSI which is Ford’s recommendation for front and rear cold pressures in the OE tire size. While you can increase your rear pressures, based off of Ford’s recommendation 65 PSI meets the rear load capacity. Toyo Tires only offers recommendations based off of the vehicle manufactures approved pressures.

That's not an answer. I wrote them again and asked if they could supply a load vs pressure chart. I've attached it to this post.

Typically, I will inflate the tires to 5 psi below the max pressure shown on the sidewall. I average 40k miles overall on a set of tires.

I'd like to hear other opinions on this. Do you leave the tires at the recommended pressure no matter what the load is you will be towing/hauling?

 

I run 45 Empty,

and 65 front and 80 rear LOADED... as marked on the sidewall of tire.

you have been talking to the legal department. covers there A**
no real answers.. just corporate policy.

 

Door sticker on mine says 60 front and 70 rear, I run that loaded. Unloaded I drop the rear to 60 psi. If I run less than 60 in the front handling suffers.

 

Like the door pillar says - 65 front and 80 back. The 275/70-18 Michelins on my truck are rated at 3640 each @80psig. And a bunch more then the capacity of my truck or the pin weight of our 5er. The fronts are rated 3195 at 65 psig. By installing the optional and larger size for my 18" wheels, I gained 225 pounds of increased capacity per tire but at a slight loss in fuel mileage and ride comfort (according to my wife).

Mine are left that way JIC I haul a load. Winter, I drop the rears a few pounds...

 

I understand your point about pressure, but I am simply unwilling to continually adjust my pressures based on load and my tires wear fine. I normally get about 65,000 miles on a set of tires or darn close to it.

Steve

 

65 front ~~ 80 rear checked before every trip. Never drop....

 

My camper package calls for 75/80 psi. Per Nitto tire it is recommended that I run 62/65 when empty.

 

run 70 front and 80 on all four rears and leave.

 

Go with the pressure the guys that actually make the tire recommend.
After the Ford Explorer / Firestone disaster a few years back, to reduce or eliminate liability, the tire guys said its up to the vehicle maker to decide.

 

Explorer recommended running a lower pressure in order to improve ride quality before the tires started blowing out. It didn't work out so well.

Steve

 

The original tires on the truck are Toyos, when I wrote them about recommending a tire pressure based on load, they gave a non-answer:

"Toyo Tires only offers recommendations based off of the vehicle manufactures approved pressures."

I'm still looking for something from Ford that addresses this question. The whole issue just got my curiosity since there are so many opinions on it from owners. I myself, will continue to use the Max pressure listed on the tire sidewall or very close to it when towing or hauling loads near the trucks rated capacities. I'm giving some thought on what pressures to run in the front tires though. I'd like to know how much of the pin weight from the 5th wheel is transferred forward. Where can I get weights on everything. Front axle, rear axle, pin weight, trailer weight?

It doesn't seem logical to keep the same pressure running fully loaded as with no load. The sidewalls will have to flex more and the flexing will generate heat. I've never seen any unusual wear on my tires although I've never come close to getting 65,000 miles from a set like RV_TECH does. 40,000 is the best I can expect from the originals. My 2006 F-250 came with Goodyears. When they neede replacing my Ford dealer had an offer I couldn't refuse so I replaced with the same model Goodyear.

RV_TECH: If your reading this could you tell us how much of the 65K miles is towing vs normal driving and what brand do you buy.



Thanks

 

On my trucks I only run Michelins.

On my service truck, which has a bed slide and barn door cover, it always has over 1,000 pounds in the bed with generator, and tools, I am just getting tires this Friday with 69,000 miles on the odometer.

My dually also has Michelins, but had Coopers and I had over 65,000 miles on them before I arbitrarily bought an entire new set of Michelins. They could have easily gone more miles. Unfortunately I can't speak to durability with this set as they are too new, but that truck is towing more than running empty, but it does so in bursts.

Absolutely not trying to start a tire war. I don't care which brand tires folks prefer. Michelin is simply my preference.

Steve

 

My understanding is that if you're running a tire similar to the OEM tire (size, load range) then you follow the truck mfg recommendations, the label on the door frame. Sizes other than OEM? You're on your own.