Tires: Correct Tire Inflation, michelin pilot sport, 17 rims

Question
Hey !
I have upgraded the wheels on my vw golf . Now i have 17" rims with  Michelin Pilot Sport tires ( 225/45 ZR17 91Y ). The sticker on my car reffers to 15" and 16" rims , so i don't now if they are under-inflated or over-inflated.
I inflated them to 33psi and i think they are under-inflated , can you tell me how much should i inflate them ?  Thank you !

Answer
Mario,

The placard on your vehicle is the starting point for the calculation.  You need those values (the tire size and the inflation pressure), the load tables (which are only published in a booklet, which I have) and the new tire size (which you've supplied).

Alternatively, the year, make and model of your car is listed in a book called "Tire Guides", that summarizes the placards in a convenient form.  However, Tire Guides does has some errors, so it's best to use the vehicle placard.

Post back with the tire size and pressure listed on the placard, and I'll answer your question.