I dont have a manual and Im trying to win 1 on ebay, but I have GTA wheels but I got 16" in the back and 15" in the front. What would be the correct tire pressure level for a 245 50 16" Tire and for the front which are 215 65 15". Thanks

 

in my humble opinion it would depend on the tire . the tire maker puts the suggested press. on the tire sidewall . i normally follow the mfgs. advice . general rule is about 35 p.s.i. + or - 2 or 3 . good luck .

 

the # on the side wall of the tire is the maximum pressure the tire can hold. not the suggested pressure. my 87 gta with 245/50r16 wants 30 psi. i have it at 35 to get better gas mileage or 30 for a slightly smoother ride(dont knotice a big diff between the 2 presssures) basically the higher the pressure the harder the ride and better gas mileage also good if ur gonna have alot of wieght in the car. lower the pressure and it will be smoother but at the cost of gas mileage.as for ur car its hard to say what is right or wrong as u have 2 totally diferent tires on the car. i would say anywhere between 30-35 is all u need mabey have more in hte front to compensate for the taller sidewall tire in the front.but look on your driver door vin sticker. it should tell you the manufacture sugested pressure.

 

don't look on the driver door. the door could have been replaced causing it to be wrong. and all tires are different, the door is for the tires that came with the car, if you replace the tires the doors are then wrong. so look on the sidewall of the tires, thats your best bet. but yea, most cars are 30 - 35 psi

 

you are corect, the doors could have been replaced meaning they may be for the wrong tires, but the sticker does have the tire size and speed rating, if your tires match the size and speed rating that the door says then the pressures the door states is correct. in this case because the tires are different from front to back, the door sticker is, in a sence, useless. and yes most cars are 30-35 psi. But, the # on the side of the tire means the tire can safely handle that amount of air pressure.(the tire could handle more air but its not safe) that is all it means. its the maximum pressure. the manufacture of the tire doesnt make a tire built for that specific car.

 

I worked in the tire business for years, and common accepted air pressure in any given passenger vehicle is 32 psi for optimum gas mileage and ride comfort.

 

All my cars where always around 32 psi, even my blazer was at 32 psi.

32 psi is a good pressure if the car is not heavily loaded.

 

Recommended tire pressure for both 16" and 15" rims is 30 psi per the manufacturer. Spec should be more the recommendation of the car manufacturer and the tire manufacturer to a lesser degree. Found out the hard way that running your tires at 35 psi regardless may cause premature tire wear. My BFG Radial T/As wore out in the middle at 29,000 miles.

 

The following is a quote from the RMA(Rubber Manufacturers Association):


<li type="disc">Make sure you check your tire pressure regularly – at least once per month and before every long trip — including the spare and keep it at the level recommended by the vehicle manufacturer.<li type="disc">The correct cold inflation pressure for your tires is listed on the vehicle label on the door post, fuel door, glove box or in the owners’ manual. “Cold inflation pressure” refers to the pressure in a tire that has not been driven for at least three hours. As tires warm during driving, it is normal for pressure to build up. Never “bleed” or reduce air pressure when tires are hot.<li type="disc">The tire pressure listed on your sidewalls is the maximum pressure and is not intended to serve as notification of the correct pressure.<li type="disc">Under inflation creates excessive stresses and heat and may lead to tire failure. It is also important to guard against overinflation, which can cause uneven wear plus handling and stopping problems.



All tire manufacturers state that you should use the tire pressure setting listed on the door jamb/owners manual. It drives me apecrap when I buy new tires for them to put 36# in them. It also drives me apecrap when "professional" tire people say to use the pressure listed on the sidewall.

 

I run 35psi in both my IROC and GTA rims.

 

 

ITs best to READ the pressure chart on the side of the tire!

One P rated tire may be 35 while a LT rated tire may be 80 psi.

 

Sonjaab -

I used to believe that. But I now believe that the auto manufacturer knows the best pressure for the weight and performance of your vehicle - at least as much as a tire manufacturer whose tire is applied to MANY different vehicles.

 

That's not the case. Granted that this refers to a truck, but my Silverado came from the factory with P rated 265/70-17 tires with a max rating of 44 psi. I think my max load was 7800 pounds. The door placard said to inflate to 35. That's fine under a normal load, but at max load, I need to inflate the tires to max pressure of 44 to support the load. Now, my new LT rated tires are set with a max pressure of 80 psi. If the max load the tire can handle requires 80 psi, then the normal load calculates to 42 psi. The LT tire at 35 is under inflated, so the door placard doesn't work if the tires aren't the same.

 

I reckon you should just do what you think is right. Me? I'll listen to the RMA engineers and auto manufacturers.