I got 40 series, it says max 45psi under total load or whatever. Of course im not carrying a heavy load, so what should i set the psi to?

I think factory tires are like 30 pounds, so I would probably go with 35.

ive always been told factory air pressure plus 2lbs per size of tire your gone up. so if you have factory 16s they ask for 32lbs, so with 18s id go with 35 or 36 lbs as long as it doesnt exceed the recommendation of the tires.

I'm on 225/40 18's, and I've been using 42 psi on all four tires with no problem. I was told to use a minimum of 40 psi - we don't have much sidewall to absorb impact, so it makes sense to me if you want to protect your wheels.

I think of it as a bicycle - mountain bike tires are very hard at 40 psi, but they have a 'higher' profile. If you put the same 40 psi in a road bicycle, which have very thin, 'low' profile tires, forget about riding it - the tires are basically flat. Those tires need upwards of 100 psi to be properly inflated/protect the rims.

I wish I understood the theory behind air pressure, but I hope this helps!!


1998 Eclipse GS

It also depends on the Manufacturer. I'm on Dunlops. 215/45-17. Max pressure on those is 51 I have been keeping them at 40-41 and have dead even wear across the tread. BFG's are a little lower in the max press. (least the Comp T/A's I had were) kept them at about 36-38. Read sidewall and these posts and then pick a pressure. Or call manufacturer and talk to some techno geek that probably doesn't even have a license much less a car and he can tell you proper pressure! :+

:cheers

yea i do 40 psi