Just got 4 Cooper 215/70/15 Weathermaster s/t2 mounted. Just wonder what is the correct air pressure to use?

 

Are they 225's or perhaps 33's?

 

Start with the recommended pressure on the door jamb.

 

Id start with the recommended pressure on the tire sidewall.

 

This is the standard for stock tires. Comparing to the tire itself is good. When in doubt, contact the tire manufacturer. There my be here or another 4x4 forum a note and/or calculation based on tire weight rating and the actual weight of you vehicle.

In otherwords, look for concensus, one anecdotal answer may not be correct.

 

You trollin?

 

That's maximum pressure for the tire. It will ride like a lumber truck.

Always start with the recommended pressure for the vehicle and go from there. Search "chalk test" to fine tune your pressures.

 

wrong

 

typically you want to go with whats on the door jam

 

Its safer to go by what the tire says vs the door,The reason i say that is remember the big firestone ford lawsuit about the ford explorers blowing tires and rolling?Ford said to run less air pressure so the explorer rode smoother but it caused extra wear on the edges of the tire leading to the blow outs.

 

I didn't know that! I used to work for firestone and one of their big things was make sure you air the tires to what the sticker says on the inside of the door... I did notice that the manufacturers will label what size tire and state the air pressure. So I guess with a diffirent size tire I would look up the recommended pressure.

 

I've only ever seen max pressure on the tyre sidewall, so check carefully.

 

Pressure on the tire sidewall --.

LOOK UP THE DEFINITION OF MAXIMJM!

 

You should always go by what it says in your door jam. The number on the tire's sidewall is maximum PSI, and remember you're filling the tire cold. If you fill to max and then start driving around, it'll expand a bit.

If you're running a non-stock size, use the door's recommendation as your starting point and tweak from there.

The proper air pressure for Cooper tires is 0, as you should bring them back and get some tires that will actually balance well

 

I wonder why the guys at Discount Tire recommended using the jamb sticker then. Perhaps you should contact them and set them straight.