i remember putting 8psi below max on my girlfriends 98 mustang and the tires on one side developing bubbles and sears blamed me for it saying the pressure was higher than the sticker inside the gas door.. which to me sounds like crap because there completely different tires then stock..first of all the cars a V6 with GT rims and tires so sticker thing sounds like bull i put 32 psi when tire says 45psi max .. i think the tires are defective to cause a bubble..what do you guys think? he said they should be at 28psi


on a side question what should i set my pressure on a 17's pony rims?
what do you guys set yours i got the pirelli pzero's

 

The P-Zeros themselves say 51 psi max cold. I have fallen into using the tire manufacturers info as a guide because my previous Dodge product had had the tire guide removed and I can't find one on my wifes car or my truck. But there was no way I was going that high on my Mustang because it would drive like a Jeep.

Then I remembered this is a Ford and they put the tire pressures settings on the inside door edge. In this case it's 32 psi cold. I'll go with the car manufacturer over the tire company as this is the setting that the car's suspension was designed at.

 

Yeah runnin 8 below tires max psi didnt cause it. Either it was a defective tire, or she was hitting curbs or potholes. Hard to say without seing it.
The tire will only tell you the Maximum pressure it can hold. Unless you are weighing the car down to a full load you should not run the Max psi. Like 06Vista said it would ride like a jeep.

 

this question is a good one.the other day I went to check pressure and it was something like 44psi max(BFG) and inside driver door well it says 32psi :scratch: they had 32 psi in them so I kept it at that.I started thinking of the whole Firestone fiasco with the Explorers and said to myself "No way would FORD screw this tire thing up again after having their hineys handed to them" but then again,it is FORD...............what do you guys think??

 

32 psi for as long as I can remember...and that's longer than some of y'all have been around.

 

Doesn't V6 say 34 or 36 PSI?

 

the bubbles were both on the driver side on the sidewall of the tire

 

The tire pressures listed on the door jamb are just factory recomended pressures for the factory tires.. Once you change the tires, its not accurate...

The max pressure listed on the side of the tire is the maximum amount of pressure you can put in the tire which will then also give you the maximum amount of load carrying capacity of those tires..

You can find the abogirl of ill reputee minimum tire pressure you should run by doing a little math..

Lets assum the mustang is 3500 lbs.. you are 200lbs and you sometimes carry a passenger (another 200 lbs).. I'm assuming no luggage, ever... that comes out to 3900 lbs..

Lets assume your tires are rated to 1440 lbs at 44psi max.. That means that at 44psi your 4 tires can handle 5760 lbs max..
3900 lbs is 67% of 5760 lbs.. Soo.. the absolute minimum air pressure you can run and be able to carry the weight is 67% of 44psi or 29.48 lbs..

Again, these are the absolute miniums.. That means you must run pressures higher than that to carry the weight of the car + people.. Also, this is assuming a 50/50 weight distribution (the mustang I think is 65/45)..

The correct pressure is not 29.48lbs.. you still need to figure out the correct pressure which is more based on driving style etc.. You can to the chalk test to find out what the correct pressure (for tire wear) is.. but you can still tweek it from there to match more your driving style..

~Mark

 

Here is another trick to get the correct tire pressure for you car. Take a white piece of chalk and mark a line on your tire treads from one side to the other. Then drive the car enough to run over the chalk line on the tire a few times, and look at the chalk line. You should be able to see if the tire is over or under inflated. Then adjust the air pressure as needed. Might take you about 5 minutes or less per tire. PS. remember to do this on cold tires. When the chalk line wears evenly all the way across the tire tread, then you have the proper air pressure in that tire.