Tires: Proper Tire Inflation, proper tire inflation, load tables

Question
If I have a much larger upgraded wheel/tire size on my vehicle how should I determine the proper tire inflation in psi?  Should I still assume the spec on my datacard located in the door well is correct?  Thanks

Answer
Jeff,

If you are using a tire size different than what is on the placard, then it is no longer applicable.

The calculation for the new pressure is not difficult but you have to have access to tire load tables which are difficult to find.  If you'll post what the placard says for size and pressure, and what your new tire size is, Ill do the calculation for you.