I have a 2006 M6 with the V6. I traded in the stock Michelin 215/50-17 (a grand touring grade tire) for 225/45-17 Pirelli P Zero Nero m+s ( rated ultra high performance 4 season). In my Canadian winter I run on 205/55-16 Dunlop Sp Winter Sport M2. The door sticker from Mazda says 32 psi tire pressure. Should I change since I have different size tires now.
Mazda manual recommends 4 more lbs for snows, but that may be for 215/50-17 snows. I normally pump another 3 to 4 lbs than what the manufacturers suggest for better wear and handling.
Also, is there any general rule on tire pressure when you switch to larger wheels.
Thank you.

 

on your new tires, look at the sidewall markings and that will give you the optimal tire pressure, and then from there you could pump them up a little more depending on how you want your ride to feel.

 

Clean your tires and put a very thin layer of talc down on the ground. Roll your vehicle through the talc and take a look at the contact patch of the tire (you should have an even layer talc everywhere on the tire where it contacts the ground.) If the tire pressure is too high, you'll notice talc not getting onto the outer edges of the tread.

 

sslature...that is an awesome idea... I love that!

 

I concur, that is one the most creative car care ideas I have ever heard!

 

yeah, sstlature, your system beats my system of trial and error by far. good thinking.