i have a 2008 G35X stock and i've been checking my tire pressure and i noticed the dealer has set it to around 38psi when the car is cold. The label on the driver side door says 33psi for both front and rear.

What is the correct tire pressure?

i also know there is a calculation from modified mag for every 100 pounds = 1 psi

ie 3700lb /100 = 37PSI and + 2 PSI all around +2 psi for the heavy end.

works out to 39PSI for rear and 41PSI for the front

so i am guessing the dealer is right and the car's label is wrong?

 

could it be that before when i went to the dealer to service (about 2 months ago) it was still cold and now that summer is finally showing up, it makes the difference?

 

The manufacturer recommends a tire pressure based on weight, the car's handling characteristics, tires, etc. You should go with the mfg recommendation (plus potentially go up a pound or two for better handling - I run 34 in mine).

 

i run 34 - 35 psi also

 

Humm I was running mine 33-34psi, I think I'll go up to 35psi

and btw you should always measure your pressure when the car is cold or tyres are cold because when they're hot they will be higher by several psi's

 

I've always inflated mine (cold) to 33psi. After recently gaging the tread depth I have found the side treads have worn an avg 1/32 more than the centre so I think I will start inflating to 34.5 or 35 psi for a while. I have about 22000km (13670mi) on these OEM Eagle RS-A tires. Not a great tire but not awful either. They have 6to7/32 left. I think they where 9/32 when new.