# Tire pressure for hauling wood



## Black Jaque Janaviac (Apr 21, 2010)

I can't remember where I've read it but for some reason it stuck in my mind that for hauling loads one ought to run at max tire pressure.  I assumed this meant max tire pressure as listed on the sidewall of the tire.

I recently had a vehicle in for rotations and the guy at the shop seemed concerned that my tire was at max.  He said to go with whatever was listed on the driver's side door which is always much less than what's on the tire.

What is the wisdom on tire pressures?  Do you go with what's on the truck door or tire side?

How does this relate to:

fuel economy?
tire wear?
traction/performance?
load hauling?


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## Flatbedford (Apr 21, 2010)

On all of the 3 F250s I have owned the sticker said tire size is 235/85-16 LT and the pressure should be 80 psi, the same as is stamped on the tire. Maybe on lighter trucks with the "P" rated tires there are different numbers on the sticker than the side wall. Usually the maximum load the tire is at the max pressure. While that might be higher than what is recommended on the sticker, if you are running with the truck heavily loaded I would go with the tire's max pressure. Running empty, you might want to go back down to the recommended pressure to soften the ride a little. As far as wear, an under inflated tire will wear faster due to the generated heat and give poorer fuel economy due to increased friction. Soft tires will also allow more sway than properly inflated ones.

There's one guy's opinion. I'm sure there will be more.


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## Deere10 (Apr 21, 2010)

On the sticker is vehicle mfg specs for ride ,fuel mileage ans so on..   If you go to what the max tire spec is you will wear the center of the tires out fast.. OK to inflate to haul wood to compensate for sidewall squat. Just to remember to drop it down when done is all or you may be buyin tires soon...


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## Black Jaque Janaviac (Apr 21, 2010)

I'd like to say I can trust the tire guy.  But hey, he makes his money selling tires.  So if 35PSI will increase the wear. . . 

Yes, the vehicles that I run all have the "P" rated tires and it's not unusual to see differences between the vehicle's sticker and the tire's sidewall.  The tires themselves commonly list "44 PSI" as the max or maybe "42 PSI".  The sticker on the inside door of the vehicle contains the GAWR using PXXX tires, and YYY rims, inflated to "35PSI".  

So it's not just a pound or two difference it's closer to a 10 PSI difference.


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## loon (Apr 21, 2010)

not sure if this will help you out?  but lots of information here..

http://www.tirerack.com/tires/tiretech/tiretech.jsp


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## Backwoods Savage (Apr 21, 2010)

Many moons ago we had a fleet of trucks and we bought a bunch of new radial tires. They were awful as you had to be steering those trucks constantly and it reminded me of being on a waterbed. One day I was driving and stopped at a little garage (I knew the owner) and asked his opinion because I wanted to run higher air pressure. He told me that many had stopped asking the same thing and said they all exceeded the recommendations but it solved the problem. So, I socked a bunch of air into all those tires but do not remember for sure how much pressure I put in except to say that I'd never ever heard of that much air in a truck tire. It solved the problem.

So, how did that affect the tire wear? Common wisdom says the center of the tires would wear faster. Experience said baloney! We got excellent mileage from all those tires once we got extra air in all of them. Our tire man came out with all the warnings when he found out about it and he did not like it. Of course, he did not make as much money either because the tires started lasting us longer. 

Even on our car I tend to run a bit higher pressure than recommended and have had no problems with uneven wear. As for gas mileage, it probably helps a little but very little. As for traction, I expect it is like the gas mileage in that it affects probably a little but not enough to make any difference. I've done this now for well over 30 years with both trucks and cars. Heck, I even run the atv with more air than recommended.


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## mayhem (Apr 22, 2010)

Listen to your tire guy.

If you are running the right tires for your truck, I'd say the max pressure on the door sticker is where you ought to be at.  That number isn't arbitrary, its a calculated and tested number to allow to carry the maximum capacity as safely as possible.  if you overinflate your tires to try and make up for sidewall squatting then you're probably overloading your truck and can start compromising other systems like handling and braking.

When i say the right tires for your truck, I mean not running 6 ply tires on a 3/4 ton truck that calls for 10 ply.  The P rated tires you're using on your truck may also have applications on slightly heavier duty trucks...like a half ton instead of a Ranger or dakota for example...that vehicle may call for 42PSI, so the manufacturer designed the tire for a variety of applications.  You should always go by waht your vehicle sticker says for tire pressure.


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## Black Jaque Janaviac (Apr 22, 2010)

Interesting.   I read what Tire Rack had to say.  And they recommend going with the vehicle's recommended pressure instead of the tire's pressure.

However, my truck, Dakota quad cab, lists P245 r16 on the door.  The tires I have are P265 r16.  I recently replaced my tires too.  I just replaced 'em with the same size tire that was on the truck when I bought it - I never bothered to look on the door.  

So, the manufacturer recommends 35 PSI using a P245, but I've got P265 instead.  So now what?

P.S. they're alloy rims if that factors in at all.


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## DiscoInferno (Apr 22, 2010)

I recall from the Firestone/Ford fiasco several years back that Firestone accused Ford of putting too low of a PSI on the door sticker to improve ride comfort, which Firestone claimed contributed to the tire failure.  Not sure if the claim had any merit, but at least in that case the tire manufacturer wanted more pressure.  My 96 Ranger came with the "bad" Firestones, door sticker is 35 PSI.  They hit 70,000 miles right when the recall happened, so I got 5 free Goodyears.  Lately I've been filling them to 40 PSI (tires say max is 44 I think) to make up for letting them sag down to 25-30 too often.  Didn't notice the ride get much different, but did see my mileage go up maybe 1 mpg or more.


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## Cowboy Billy (Apr 22, 2010)

My younger brother work at Roush Racing. Several years ago they sent him down to a ford test track in florida to do some work. He ask the engineers there why the tire pressure was so low on the explorers. They told him it was so the tire would start rolling onto the side wall and start squealing when it was close to a roll over situation.

On the other hand I always run my tires at max pressure in the summer and drop it back in the winter. As long as the truck is aligned correctly I have never had a problem with tire wear and I get more the the rated milage on the tire.

Billy


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## Black Jaque Janaviac (Apr 22, 2010)

As I was thinking of some of the responses on this thread a question popped up about wearing out the center tread.

I would think that the tire manufacturer would set the maximum tire inflation at a point below that which would cause excessive tire wear.  

Keep in mind we're talking max pressure NOT overinflation.


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## Highbeam (Apr 22, 2010)

Not really. See the tread of the tire will lay flatter on a heavier truck. The tire manufacturer has no way of knowing how heavy the truck will be or what load the tire will see. The same tire should be run at different pressures for optimum tread contact when loaded differently. Truck manufacturers must set a compromise pressure that falls somewhere between empty and loaded pressures. They know that most owners seldom load their half tons to the max so the stickered pressures correspond to an empty truck.

Tire pressure is simple. If your contact patch with the ground is 100 square inches and you have a 1000 lb load placed on your tire then you will have 10 psi in that tire. Get the math? If you inflate the tire to 20 psi then your contact patch will shrink to 50 square inches and the outside of the tire tread might not even tough the ground which leads to faster center wear. 

I run max tire pressure all the time since I would rather have slightly higher tire wear, better mileage, cooler running tires due to less flex, and lots of load capacity all the time. Yes, my ride quality might be a bit stiffer but it's a one ton truck. 

Remember that the max tire pressure on the tire is for when the tires are cold. Like in the morning before you go to get the wood. Tire pressure in will rise as you drive and the tires heat up.


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## daveswoodhauler (Apr 22, 2010)

Highbeam said:
			
		

> Not really. See the tread of the tire will lay flatter on a heavier truck. The tire manufacturer has no way of knowing how heavy the truck will be or what load the tire will see. The same tire should be run at different pressures for optimum tread contact when loaded differently. Truck manufacturers must set a compromise pressure that falls somewhere between empty and loaded pressures. They know that most owners seldom load their half tons to the max so the stickered pressures correspond to an empty truck.
> 
> Tire pressure is simple. If your contact patch with the ground is 100 square inches and you have a 1000 lb load placed on your tire then you will have 10 psi in that tire. Get the math? If you inflate the tire to 20 psi then your contact patch will shrink to 50 square inches and the outside of the tire tread might not even tough the ground which leads to faster center wear.
> 
> ...



Great advice and explanation HB.


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## Black Jaque Janaviac (Apr 22, 2010)

After looking into this it appears that:

The pressure listed on the vehicle door is a minimum, the pressure listed on the sidewall of the tire is just as it states, a maximum.  Running pressures in between these is not going to be dangerous, however it may not be optimal.  The driver can decide which is best based on his driving needs.  For average uses the vehicle manufacturer's recommended pressure is probably closer to optimal.  

Would I be correct in saying that to stay within the door-label and the sidewall pressures would be safe and the worst that would happen is you'd wear the tire out faster, get less gas mileage, or have a rougher ride?


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## billb3 (Apr 22, 2010)

Black Jaque Janaviac said:
			
		

> I can't remember where I've read it but for some reason it stuck in my mind that for hauling loads one ought to run at max tire pressure.  I assumed this meant max tire pressure as listed on the sidewall of the tire.
> 
> I recently had a vehicle in for rotations and the guy at the shop seemed concerned that my tire was at max.  He said to go with whatever was listed on the driver's side door which is always much less than what's on the tire.
> 
> ...



I've always considered the  recommendation on the door was for the truck and a driver.
Anything different from that would require adjustments.
When I had a camper bolted  on the bed  I'd have to pump them up or I'd get horrible mileage.
Never put exactly max in, but got close.

When the camper came off I'd drop the pressure back down.


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## jklingel (May 10, 2010)

I can't see how anything on the door could be for anything other than the tires ALLEGEDLY shipped with the truck, if that. I've never read the door info, because the same rig can be sold w/ different tires on it. Full pressure w/ a heavy load, a bit less w/ lighter loads. The TIRE should drive the pressure, as it is manufactured to operate in a particular range of pressures, and no manufacturer knows who will be running what tire on what rig. My tire guy says he has been running 10 psi OVER max, to save gas, for several years. Is that wise? Dunno. I won't do it.


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## wendell (May 10, 2010)

Cowboy Billy said:
			
		

> My younger brother work at Roush Racing.Billy



Would you please have him tell Jack to get his butt in gear and get his cars faster. I'm getting tired of losing!  :shut:


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## Gooserider (May 10, 2010)

In various past jobs I've done gas / tire jockey at one of the old fashioned "Full service" stations - the kind where they actually checked tire pressures!  We also sold a lot of tires.  What we always were told is that the tire info lable was always for the tires the vehicle MIGHT have come with, and didn't really apply to any other tires, we were far better to run up to max or close to it, especially since on most cars (other than our "regulars") the tires were WAY soft....

I will also say that I don't think I've EVER seen a tire wear out in the center - they go soft and wear on the sides first 99 times out of 100...  

Bottom line, I run at tire sidewall max or close to it, and advise others to do the same...  

Also note that there have been a lot of tire design changes over the years, and even in the same size, the optimal pressures have gone up, so especially in older vehicles, you will be far closer to optimal running near sidewall max...

Gooserider


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## fbelec (May 11, 2010)

i've been running max pressure for years. i have never worn a tire out in the middle. the last time i seen a tire worn out in the middle from over inflation it was the old bias ply tires. most cars and trucks you will find even if the car or truck is aligned proper to specs will wear the tire out on the outer edge. you will notice this if you don't rotate your tires. i run my tires on max for depending on pressure difference 15% give or take 5% better fuel mileage. and i have never blow out a tire running at max pressure. 2nd reason i run at max is how the vehicle handles a corner. my truck gets mushy on corners and the highway if run at 55 pounds my tire guy set them at i run 80 psi cold. my car is a old crown vic. when the tires are run to the sticker on the door, i can't even corner the car at 15 miles per hour and exit ramps were very slow and squealing. run them up to 35 max and it is fine. the car is suppose to get 14 mpg in the city with it's 5 liter motor. and it does. inflate them up to 35 pounds, max of tire and i'm getting 17 to 19 city miles per gallon. and as far as how long the tires on my truck last. the last set of tires were 40,000 mile tires. i got 58,000 miles out of them. i run with a ton of stuff in my van always. my firewood guy around the corner was delivering loads with his tires at 55 lbs of air and almost rolled the truck. they may have well not put a sticker on the door of any vehicle because the same vehicle can have different tires on them right out of the factory and when you have the tires changed to a different brand or different style because the tires that came on the car are not made anymore makes that sticker useless.
$3.00 a gallon should be a good enough reason to run at max pressure.


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## ewdudley (May 11, 2010)

We made another turn and almost rolled again. The Coupe de Ville is not your ideal machine for high speed cornering in residential neighborhoods. The handling is very mushy...unlike the Red Shark, which had responded very nicely to situations requiring the quick four-wheel drift. But the Whale -- instead of cutting loose at the critical moment -- had a tendency to dig in, which accounted for that sickening "here we go" sensation. 

At first I thought it was only because the tires were soft, so I took it into the Texaco station next to the Flamingo and had the tires pumped up to fifty pounds each which alarmed the attendant, until I explained that these were "experimental” tires.

But fifty pounds each didn’t help the cornering, so I went back a few hours later and told him I wanted to try seventy five. He shook his head nervously. “Not me,” he said, handing me the air hose. “Here. They’re your tires. You do it.”

“What’s wrong?” I asked. “You think they can’t take seventy-five?” He nodded, moving away as I stooped to deal with the left front. “You’re damn right,” he said. “Those tires want twenty eight in the front and thirty two in the rear. Hell, fifty’s dangerous, but seventy five is crazy. They’ll explode!” I shook my head and kept filling the left front. “I told you,” I said, “Sandoz laboratories designed these tires. They’re special. I could load them up to a hundred.

“God almighty!” he groaned. “Don’t do that here.”

“Not today,” I replied. “I want to see how they corner with seventy-five.” 

He chuckled. “You won’t even get to the corner, Mister.”

“We’ll see,” I said, moving around to the rear with the air-hose. In truth, I was nervous. The two front ones were tighter than snare drums; they felt like teak wood when I tapped on them with the rod. But what the hell? I thought. If they explode, so what? [...]

As it turned out, the Whale behaved very nicely with the altered tire pressures. The ride was a trifle rough; I could feel every pebble on the highway, like being on roller skates in a gravel pit ... but the thing began cornering in a very stylish manner, very much like driving a motorcycle at top speed in a hard rain: one slip and ZANG, over the high side, cartwheeling across the landscape with your head in your hands. 

--H S Thompson


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## granpajohn (May 11, 2010)

ewdudley said:
			
		

> We made another turn and almost rolled again. The Coupe de Ville is not your ideal machine for high speed cornering in residential neighborhoods. The handling is very mushy...unlike the Red Shark, which had responded very nicely to situations requiring the quick four-wheel drift. But the Whale -- instead of cutting loose at the critical moment -- had a tendency to dig in, which accounted for that sickening "here we go" sensation.
> 
> At first I thought it was only because the tires were soft, so I took it into the Texaco station next to the Flamingo and had the tires pumped up to fifty pounds each which alarmed the attendant, until I explained that these were "experimental” tires.
> 
> ...



Thank you for that EW. I was reading this post thinking "what is this guy on about? How strange" Then about half way through I got the feeling I had read this style of writing before, and think "this is from one of those Fear and Loathing books - Hunter S. Thompson"; and Yes! it's true.
Thanks for the 1970 (+/-) nostalgia.
Note to young people: read it, he's funny and talented. And remember: When you're doing that many reds, you need all the vitamin C you can get.


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## Bigg_Redd (May 11, 2010)

Black Jaque Janaviac said:
			
		

> I can't remember where I've read it but for some reason it stuck in my mind that for hauling loads one ought to run at max tire pressure.  I assumed this meant max tire pressure as listed on the sidewall of the tire.
> 
> I recently had a vehicle in for rotations and the guy at the shop seemed concerned that my tire was at max.  He said to go with whatever was listed on the driver's side door which is always much less than what's on the tire.
> 
> ...



I always run the max listed on the sidewall of the tire.


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## triptester (May 11, 2010)

Beware when exceeding the recommended pressures on tires for extended periods of time. There are recommended pressures listed on the door pillars of vehicles these are mainly for ride comfort and within the ratings of all components. The max pressure listed on tires are cold pressures they can raise significantly after traveling greater distances.
One thing that is never considered is what the max. pressure rating of the rims are. I have seen rims that have split due to running tires that were rated for high pressures but the rims were not.


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## TreePapa (May 11, 2010)

> I always run the max listed on the sidewall of the tire.



I tried to fill the (14") tires on my '94 Ferd Ranger to the 35 lbs listed on the door sticker. The wimpy pump at the local self-serve Chevron would NOT get them above 32 lbs for love or money. This is one of those pumps off to one corner of the gas station. Cheveron is almost the only chain around here were the air is free ... most others charge 75 cents or a buck. I don't think there are any actual *Service Stations* left around here where you can fill your tiers wtih the air pumped from the garage's main compressor like the old days.

I have a little Ryobi 18v compressor that will get the tires up to 35 lbs if I'm patient, but if I ever upgrade to the 16" load-rated tires I really want, I'm gonna have to buy a real compressor too.

Peace,
- Sequoia


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## ROBERT F (May 24, 2010)

15+ years as a "tire man" speaking here.  P rated tires, not designated with an "extra load" in the service description, have the max load capacity listed on the sidewall.  that rating is at 35 psi, even if tires max inflation capacity is say 44.  running more air does not increase load carring capacity.  makes the ride stiffer and makes the tires footprint smaller.  wich in turn equalls longer panic stopping distances and more road shock transmitted to the vehicle, and its bearings in particular. in black jacks case, running the larger tires, his larger tires actually carry just slightly more load than the o.e. size at the same pressure, but it is frowed upon to run less than the tire placards listed pressures.  can you run more air than the tire placard? yes. (never less).  will it affect tire wear? only slightly.  will the vehicle sway less when fully or overloaded? yes.  The tire placard, when used in conjunction with the listed tire size, will carry more than the vehicle itself is capable of carrying.  Just to clarify, you can always run more air if ya wanta, but it will only increase load capacity up to the 35 psi mark on non extra load p metric tires.  after that its just more air.


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## mayhem (May 28, 2010)

granpajohn said:
			
		

> ewdudley said:
> 
> 
> 
> ...



This is actually the first bit of HST I've ever read in my life...never heard of him till he died and couldn't figure out why people were upset by it.  I had alot of trouble just getting through this short bit and really didn't find it very entertaining at all.  But fair enough, I'm going to locate a copy of one of his books and give it a fair shake.  Any one book that anyone can recommend?


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## jebatty (Jun 2, 2010)

Not a truck, but for my car, I run the radials at 35-40 psi. Door sticker says 30. Check my math, but if I get 40000 miles on a set of tires, and if I get 29 mpg at lower inflation, that's 1379 gal of fuel. With the higher inflation I get 34 mpg on highway driving, which is 1176 gal of fuel, or 203 less gallons. At $3/gallon, that's $609. I figure that comes really close to paying for the tires.


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## granpajohn (Jun 2, 2010)

mayhem said:
			
		

> This is actually the first bit of HST I've ever read in my life...never heard of him till he died and couldn't figure out why people were upset by it.  I had alot of trouble just getting through this short bit and really didn't find it very entertaining at all.  But fair enough, I'm going to locate a copy of one of his books and give it a fair shake.  Any one book that anyone can recommend?



For lack of better....I'll suggest Fear and Loathing in Las Vegas. I laughed out loud for the first 5 pages and then decided to finish the whole book. I agree that the little post here is not very entertaining.
There is a series of Fear and Loathing books that I should read, but I do not read much fiction these days. (Dave Barry and J.R.R. Tolkien the only exceptions.) Put another way: Comedy is good, drama is bad; (or at least boring).
(Am I off topic? Heck, yeah.)


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