225/40 for my 17 inch wheel...

[Manic2k]

Is this tire size gonna fit?
or should I stick with 215/45?

as you have guessed, I don't know jack about tires and rims.

[liquid]

i've been using 215/40/17 which is very close to the stock rolling diameter for the 205/50/16's.. a 215/45 is a larger diameter and will give you more speedo error.. (the 45 is about an inch longer diameter tire than the 40 in that size)

http://www.2k1civic.com/stuff/tire_calc.cfm