So I went to a new tire dealer and bought some Kumho Ecsta ASX 225/40/18 they filled it to 50psi (which is the max pressure rating of the tire). I always thought to keep my tires around 35psi but didn't know why and the guy at the dealer told me that I needed to keep the tire at max psi.

Does this guy know what he's talking about? If not, what is a good pressure for my little civic and why?

 

Damn 50 PSI..... haha i would bring that back down to 32-34 PSI asap. I dont even use 50 PSI when I autocross. If this tire was meant to be at 50 psi... I havn't heard of it.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by cecknight &raquo;</TD></TR><TR><TD CLASS="quote">Does this guy know what he's talking about?</TD></TR></TABLE>

No. He's an idiot.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by cecknight &raquo;</TD></TR><TR><TD CLASS="quote">If not, what is a good pressure for my little civic and why?</TD></TR></TABLE>

The best place to start is the pressure recommended for your car. You can find this in your owner's manual. It's also usually on a placard or label somewhere on the car - either in the door jamb, or on the door of the glove compartment, back of the sun visor, etc.

Once you use that pressure for a while, you may need to adjust it (in 2 psi increments) based on tire wear patterns as well as your preference for handling vs comfort. But you probably won't end up off by more than about 4 psi from the recommended pressure. (Recommended pressures for our cars are usually anywhere from 26 to 35 psi.)