Tyre size?
 

Not starting a "what tyre is best" thread as i know how annoyee people get at them but was wondering if someone could let me know about tyre sizes?

I have a bug with what look like look-a-like pro drive wheels from a classic. The current tyres are 215 45 17. Could i get to 225? Is there any point in doing so? Im less fussed about tyre price and more about safety and performance. Thanks