Does a vibe ride really rough with 18 inch wheels on it or is it just a little bit more of a rough ride? I was wanting to get 17's but i was just curious about the ride difference with either wheel size. Thanks

If i buy custom 17 inch wheels do i have to have the hub centric rings or are they just an option?

I would like to know if I was to buy custom wheels, in a size 17" or 18", would they effect my gas mileage in any way? Also, how would each handle on the road? I have not decided on which size to buy, so if anyone has either size, give me some input on both, plez. Thanks.