gs4rocks

I just got 17X8 wheels with 235-45-17 tires. But according to tire calculator, these tires are actually smaller than 225-55-16, and the better match in diameter size is 245-45-17. I've seen many members here refer to 245-45-17 as oversize, but shouldn't this be the correct size regardless of what lexus recommended size is? I'm using oem 16' as the reference size. 235 is 1.6% off for the speedometer and 245 is only 0.2% off.