What is the ideal tire size for 18x8 rims?? benefits? Is 18x8 gonna ride better than 18x7.5?

235 40 18 <--- thats the size you want

Nope

lots of info from search...

but 235/40 if your using a 38-40 offset and 245/40 with a 35mm works.

Stick with 8" wide or even 8.5 with the 245s

according to tires.com you can use 225/40 or 215/40

DO NOT USE A 215 OR 225 ON A 18X8, no sidewall and it will look stupid becuase the tire is so small and you will put more miles on your car as well, seriously, go with a 235/40 or a 245/40 and I have a 40MM offset no rubbing and I have cut coils in the front. Looks big and sweet and smoother ride.

I'm running on 245/40's with a 45 offset.