GTSLEX

iTrader: (2)

Hi guys,

I just wanted to know what is the correct tire pressure for 245/40/18-275/35/18. I'm currently running 37 psi. My car is 01gs430

Thanks

mkorsu

Use the recommended pressure stated in your manual. Tire pressure is not directly related to tire size.


37 may be a bit high. My stock tires, 225/55/16, have a recommended pressure of 32lbs. I run mine at 33.5 out of personal preference.

rominl

iTrader: (4)

i say around 36 to 37 is good

the manual says 32psi but that's on stock wheels. with larger wheels and lower profile tires, i would recommend a bit higher pressure for more protections

mkorsu

Good point! Added protection against a dinged/bent rim!

tkrussell

Rule of Thumb is 32 to 35 psi as a starting point.
32 psi gives a little better ride, and 35 psi gives a little quicker steering response.

Usual procedure is to start with 32/32 F/R and see how it handles.
Does the front or rear tend to lose grip first?
Raise pressure on the end that is losing grip (or vice versa).
Most drivers like rather neutral, with a very slight understeer (front losing grip first),
that can be modified with throttle to give slight oversteer.

If you are just going for a nice ride, 32 is a good compromise.
As far as rim protection, anything above 30 will keep the sidewall reasonable full,
and over 36 is likely to produce increased center tread wear.

rheiy

I've noticed that my dunlop sp9000 provide the best handling at 39 to 41 psi. In the 32 to 35 range, the tires just don't feel right. sorry...not sure how to describe it.

chuckb

i say 36-----------

redgs4

I preferred to run a bit higher as well. I was running 40 - 42 on my 18's.

RA40

iTrader: (6)

On mine, 36 front and 37 rear is reasonable for my driving. I drove it at 33 psi and I could feel the sidewall flex at turn-in. At highway speeds, it followed the grooves easier too.