Tire air preasure

[kevfish1]

I put some 6 ply tires on my pickup that call for 50 lbs of air preasure. Well the ride is very rough. I took out some air and am running them at 40 lbs. much better ride. Will this be bad for the tires not running them at the max psi???

[skolfoppa]

No, but keep them rotated for even wear. Skol.

[Macgyver55]

The max pressure on the tire is not what they should be run at all the time, but merely the maximum that they should ever be inflated to with their maximum load. Use the vehicle manufacturers sticker inside the door for best ride and handling. I personally bump it up a few lbs from that for mileage sake, but thats simply a personal preference.

And, as skolfoppa said, rotate, often for the most tire life.

[BobT]

It's amazing how much life can be added by rotating regularly.

[Jeremy airjer W]

The max pressure on the tire is not what they should be run at all the time, but merely the maximum that they should ever be inflated to with their maximum load. Use the vehicle manufacturers sticker inside the door for best ride and handling. I personally bump it up a few lbs from that for mileage sake, but thats simply a personal preference.

And, as skolfoppa said, rotate, often for the most tire life.

Ditto

[SkunkedAgain]

Trailer tires need to be kept up near the max, not your vehicle tires. Hopefully someone on here can explain why.

In any case, I always drop my truck tires down to 30psi or lower in the winter. It gives me better traction and a more comfortable ride over the terrible city potholes. Since I get bad mileage in the winter anyway, it doesn't matter to me if I lose a few more MPG's to lower pressure. As soon as the snow season is over, I pumped those bad boys back up to 42psi. I've got 55,000 miles on my factory tires and still have a lot of tread left (I don't drive fast a go slow around turns though).

[Shack]

The max pressure on the tire is not what they should be run at all the time, but merely the maximum that they should ever be inflated to with their maximum load. Use the vehicle manufacturers sticker inside the door for best ride and handling. I personally bump it up a few lbs from that for mileage sake, but thats simply a personal preference.

And, as skolfoppa said, rotate, often for the most tire life.

Bingo X 2

SkunkedAgain this is not a factory run down but gives some good examples:

Advantages of Correct Tire Inflation

Maintaining correct tire inflation pressure helps optimize tire performance and fuel economy. Correct tire inflation pressure allows drivers to experience tire comfort, durability and performance designed to match the needs of their vehicles. Tire deflection (the tread and sidewall flexing where the tread comes into contact with the road) will remain as originally designed and excessive sidewall flexing and tread squirm will be avoided. Heat buildup will be managed and rolling resistance will be appropriate. Proper tire inflation pressure also stabilizes the tire's structure, blending the tire's responsiveness, traction and handling.

Can you easily identify which tire is 30% underinflated? Here is what they would look like in the morning parked in your garage.

Tough to tell; isn't it? Tire pressure must be checked with a quality air gauge as the inflation pressure cannot be accurately estimated through visual inspection.

Disadvantages of Underinflation

An underinflated tire can't maintain its shape and becomes flatter than intended while in contact with the road. If a vehicle's tires are underinflated by only 6 psi it could weaken the tire's internal structure and eventually lead to tire failure. Lower inflation pressures will allow more deflection as the tire rolls. This will build up more internal heat, increase rolling resistance (causing a reduction in fuel economy of up to 5%) and reduce the tire's tread life by as much as 25% while increasing the probability of irregular treadwear. Drivers would also find a noteworthy loss of steering precision and cornering stability. While 6 psi doesn't seem excessively low, it typically represents about 20% of a passenger car tire's recommended pressure.

Disadvantages of Overinflation

An overinflated tire is stiff and unyielding and the size of its footprint in contact with the road is reduced. If a vehicle's tires are overinflated by 6 psi, they could be damaged more easily when encountering potholes or debris in the road, as well as experience irregular tread wear. Higher inflated tires cannot isolate road irregularities as well causing the vehicle to ride harsher and transmit more noise into its interior. However, higher inflation pressures reduce rolling resistance slightly and typically provide a slight improvement in steering response and cornering stability. This is why participants who use street tires in autocrosses, track events and road races run higher than normal inflation pressures.

One thing I would add is maintaining proper tire pressure also prevents warranty and pro-rate issues if a covered failure does occur.

[jeffreyd]

The other thing is to go by the pressure listed on the drivers door or door jamb. The tire pressure on the tire is for max pressure that is allowed in that tire. The actual vehicle might call for less. I never go off the tire anymore, since the whole firestone/ford exploder issues. only by the sticker. and always check cold. a one mile drive will affect the pressure and should be allowed to cool up to 4 hrs after driven with as noted above a accurate gauge