Multiple factors there. Really depends on the tire a bit, the car, the driver, etc. There is recommend on the door from factory. But, some like me inflate to 45 in the rear 42 in the front.

 

Sorry it was 35 BUT do you on the same model as i. My tire is 215 45R 18 89 w.

How 45/42 works for you?

 

Experiment a little. Find what works for you. I used the same size as you for a long time, recently I'm on 225/45/18 simply because I needed extra cushion against potholes and it works.

 

For folks who aren't enthusiasts who like to play with such thing as tire pressure for one reason or another that they're interested in (I'm one of them), my best advice is to follow Mazda's recommendations. Mazda has tested their cars during thousands of hours and innumerable miles, and they know what's best for the vast majority of their customers under various driving circumstances.

Personally, since I am interested in getting the maximum fuel mileage possible, I generally fill my tires to the maximum psi number on the sidewalls; for my present tires, that's 44psi front and back. This is higher than Mazda's recommendation on a sticker in my particular car of 36psi, but in return, I "assume" I'm getting a little more fuel mileage. However, to get this supposed benefit, I also have a rougher ride and possibly a bit less ability to maneuver when the roads are wet, and I have to check my tires to make sure they're not wearing too much in the center as a result of the higher-than-recommended tire pressure.

That's my take.

 

Go by whatever the door says or the manual

 

I've found that I get uneven wear at mazda's recommended pressure. But perfect wear closer to maximum PSI. Go figure.

 

The max PSI on my Michelin PS4s is 51 PSI.. no way I'm going that high. The recommended level I was told to use when I got them was 38 PSI.

They are 225/45/18.
CK