well i think the biggest size of the rim that could be fit on a civic shud be the 17''. but size 17 is actualy 3'' bigger than the stock size therefore it could have some nigitive impact on ur wheel base, suspension and everything. i can remember i read it some where that u shudnt go for any more rim that is bigger for about 2'' than the standard size. so i would say go for the 16''. this way it will match the size of ur hatch back civic too.