I always couldnt under stand why people say you get slower acceleration when you swap you standard stock rims for bigger ones, as I would expect them to be the same overall size (give or take a few %) as you would use a low profile tyre. After all if the overall diametre was larger then that would mean your calculated speed would be wrong.
Anyway, I was just using the calculator on http://www.rochfordtyres.co.uk/TyreCalc.asphttp://www.rochfordtyres.co.uk/TyreCalc.asp
if I swap my 185/55/15 (dynamique) wheels an tyres for say 195/45/16 (172 ones i think) than my overall diametre would infact be -0.51% smaller