hehe... witout huge power output, even i give it 18" still can't reach 230kph in a stock Myvi loo...bro's...i think it wouldnt be so accurate on the calculations...
if ur using 195/55/15 against the new bigger rim of 215/40/17 you will experience slight decrease in pick up but better top speed due to rotational mass of the larger rims..
according to the calculator, 15' is traveling 70mph and 17' will be 73.34(roughly)...wouldnt u guys think that the 15's are easier to spin than a larger wheel?