Tires are inflated high for shipping to keep the tires from getting a flatspot in transit. Your dealer should have lowered it when they prepped the car for sale. Oops. No big deal. It's safe to run that high, and in fact I run them that high on purpose for autocross days -- keeps the sidewall from rolling under and gives you a little bit better handling response. However, it's a heck of a bumpy ride on the street. 32-35 is a good range for daily use.

 

That's great for stock rims and tires, what if you increase size to 18" or 19"? Wouldn't the tire pressure increase as well? and if so how much?

03.5 BS, 6MT, premium, 19" Kaizer wheels, Skyline badges, PIAA HID upgrade, Racing pedals, clear lenses, 35% tint, 7-wire ground, TEIN basics, side mirror blinkers, Hotchkis sways

 

I've kept my 19s at 35 all around and I have even tire wear.

Russ

Black 6MT Coupe
Jax, FL
G35Driver.com Business Cards

 

35 psi is the tire industry standard for lab testing tire performance. Doesn't mean higher is not better just not tested above 35 psi except for durability endurance test where they test at 44psi and 51psi depending on tires maximum.

Not real word to test speed and endurance with 100% load at psi almost never run by owners.

Since manufacturers usually spec tires at 80% of static load [say a 95Z =1521pounds and the sitting still no occupants is 1217 on the heaviest loaded tire] no gas, this correlates to 35 psi on a 44 psi tire and 40.8 psi on a 51 psi max tire........tires with greater reserve can use less psi and still endure.

The great the reserve between max load and real load......the safety factor......the longer a tire will last and the better able it will be to handle performance excursions which will cause momentary overloads [braking on front tires and extreme G load from turning].