[cavementech]

What tire pressures should you follow? Ford recommends one pressure and the tire manufacturer recommends a different pressure. I have recently replaced my tires to an AT but the pressures on the tires are way more than Ford recommends?

[Firefighter6484]

Go with what pressure the tire says.

Ford Pressure is for the stock tire they put on truck.
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[flyfishtn]

Tire manufacturer.

Also depends on size of the tire as well. Also, when you read the sidewall, check to see if it is max pressure or not, if so, 70% of that is good starting point.

[jwt873]

The pressure indicated on the tire is the maximum safe inflation pressure... In other words, it means danger, do not exceed this pressure. If this were the pressure the tire manufacturer wanted you to run at, then they would have labled it the recommended pressure, not the maximum. Note the difference

For instance if you have load range 'F' tires, the maximum safe pressure written on the sidewall can be as much as 95 lbs. I can't believe anyone would want to run around with 95 lbs of tire pressure on an F-150 There's a chart an the Tirerack Site You can see load range D is around 65 Lbs and it goes up from there. That's TOO much.

When you overinflate tires excessively, the center of the tread bulges out and as a result the tread doesn't contact the road evenly. Badly overinlfated tires will give you a harsher ride, provide less traction and cause the tires to wear out faster. (The center of the tread will go bald because it's doing all the work).

All the Ford factory owner's manuals I've ever read recommend using the door sticker. (They put it there for a reason didn't they ) Below is a cut and paste from my owner's manual:

SERVICING YOUR TIRES

Checking the tire pressure

- Use an accurate tire pressure gauge.
- Check the tire pressure when tires are cold, after the vehicle has been parked for at least one hour or has been driven less than 5 km (3 miles).
- Adjust tire pressure to recommended specifications found on the Safety Compliance Certification Label.

Improperly inflated tires can affect vehicle handling and can fail suddenly, possibly resulting in loss of vehicle

[cavementech]

That make sense when you have the stock tires on the vehicle. What if you upgrade to a bigger size, different brand and different style. 32 lbs of pressure is not enough in an AT tire....Do you get my point?

[fnnut]

The factory recomends a pressure based on the standard 4 ply tires that come on the f150. If you upgrade to a 6 ply like a BFG AT, the pressure will be more than the standard tire. 70% of the max pressure on the sidewall is a good starting point. Watch the tread pattern when the tire is hot and adjust accordingly.

[flyfishtn]

Cavemantech, totally understand what you mean. I just went from stock 18's on my Lariat to 325x60x18. A much bigger volume tire air-wise. I started doing research and went to Mickey Thompson website since my tires have a max pressure rating of 65 lbs, they recommend, like others do, start at 70%, drive, and adjust by the way you see the contact patch contacting the ground.

This may take a week or so to get right based on driving but it will happen. As well, as others have said, it is very important to check or adjust the tires when they are cold.

Hope this helps and please ask any more questions and we will be more than happy to answer.

I have found MANY answers to my questions here with all the great users!

[steve604]

unless you are actually hauling around some heavy stuff then don't go any higher than 40 psi. 35 psi is usually a safe bet with trucks.

i usually have 35-40 psi in my front tires where all of the weight is and 30 or less in the rear unless i'm going to haul something around. it makes for a nice ride while still handling ok. this is also with LT tires. i'm not sure what to do with P rated tires on a truck except throw them in a dumpster.
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[flyfishtn]

[f150pilot1]

Well i read somewhere an easy way to check if your tires are properly inflated is take some chalk and
mark a line across the tread then drive in a staight
line for a bit then check how the chalk has worn off
if its worn off in the center then your over inflated
if its worn on the outer edges your under inflated
and if its worn evenly your ok

[jwt873]

That's a good idea...I've never tried it, but it sounds like it should work

Another way is to monitor the tire as it wears. BF Goodrich suggests that you use a tire tread depth guage to measure the depth across the tire. Check it after a month. If you're wearing more in the middle, then you need to reduce the pressure. If you're wearing more on the outsides, the you need to increase the pressure.

Once you get the full tread contacting the road evenly, you'll have maximum traction, and your best tread life... One thing for sure though.. Whether you have the factory tires or aftermarket AT's, if you've got your tires inflated to 'what it says on the tire', then you're definitley overinlfated.

FWIW, Here's what Goodyear has to say on the subject:

"Overinflation is also detrimental to the tire. Too much air pressure causes the center of the tread to bear the majority of the car's weight, which leads to faster deterioration and uneven wear. Any kind of uneven wear will shorten the lifespan of your tires.

To find the proper air pressure for your tires, look in the vehicle owner's manual, on the driver's side door jamb or in the glove box. And if you buy new tires, be sure to learn the correct pressure from your dealer. Check your pressure at least once a month, and use a good quality air gauge. Or, stop by your local Goodyear retailer and have your air pressure checked and corrected for free.

http://www.goodyeartires.com/kyt/tireSafety/tireSafetyGuide.html