i have 18" 3 piece Volk GTUs in my car riding on goodyear shoes. checked my pressure and it was at about 25psi. Max is 51psi. Filled air to 30psi and rides much bumpier. should i lose some air?
how much air for regular street driving and how much for drag track driving??

post tires, max psi, and current psi along with wheel specs

 

It would be best to inflate them to your manufacture recommended pressure. It should be displayed in your glove box or door jamb.

 

Neal,
I always thought those high psi tires had to have the higher pressures in order to keep the proper load ratings with the shorter side walls? I didn't think they were capable of this with lower pressures. I also have assumed that "manufacturer recommended pressure" was for the OEM tire only. Anything else and it's up in the air.

Seems titanium~ problem would be because he went to 18" wheels.

Am I completely wrong here?

 

what size tire is in question?

 

I always thought that the tire pressure on the car was for when it is fully loaded.

 

Just because you plus size dosent mean you have to increase the air pressure over stock. If you use the correct plus sized tire, the amound of air that tire can hold is the same as stock. Its just held in a different shape. For example, the stock 235/45-17 has the same amount of air in it than 255/35-18. Instead of the air being narrower and taller, its wider and shorter. This way you can still run stock pressure.

 

so do i follow what my tire says or what my car says? i know my tire says max 51 psi. im at 41 now but its kind of bumpy. i had it at 28 and it was less bumpy.

 

you haven't said what tire size you are using. 18" alone isn't enough

 

i will check today.

 

mine inflated to 30 all 4 corners. 17's but as mentioned above, don't think tire size is relavant. run 30 on 18's on other car too same with most guys. Not sure what used on tracks (prolley round same) but this is what we generally use on streets when spirited driving. keep in mind psi rises with temp. 50's is prolley too high for high speed driving. lower psi, more grip to point relative to speed otherwise unbead if too much pressure. higher psi better for tire wear (on reasonable camber settings)

 

30 on all corners for 18's

 

I have Advan RG's with Azenis Sports at 245/45/17 and I have 35 psi in front and 33 psi in the rear and it sticks like velcro and it still comfortable on the freeway ( comfortable being a relative term; the Evo is a race car not a GT and it will let you know that on long trips, but I didn't buy this car for comfort) and around town unless you are on very unkempt roads it is still comfortable.