Tires: tire pressure, tire placard, 17 wheels

Question
QUESTION: I replaced the 17" wheels on my chrysler with 22" whells.  What tire pressure should I maintain in the new 22". Is it still the manufractures or the the 40 psi that the installers of the new tires put in?

ANSWER: Terry,

To calculate the appropriate operating pressure, I need three (3) bits of information.

1)  The original tire size

2)  The proper pressure for that size.

3)  The new tire size.

Items # 1 and #2 can be obtained from the vehicle tire placard, which is usually located on a doorpost or in the glove box.

Obviously, you need to tell me what item #3 is.

---------- FOLLOW-UP ----------

QUESTION: The original size was: 215/65R-17 and the recommended pressure was 30psi.
The new tire size is 265/35R-22

Answer
Terry,

In order to carry the same load as a P215/65R17 can at 30 psi, a 265/35R22 needs to have ..... ah ...... 30 psi. Isn't that interesting.

But given that you have such a low aspect ratio, it might be good to use a little more pressure to protect the rim from impact damage - say 3 to 5 psi more.