Hi everyone, great forum here. Have a question to ask.

Currently have a 09 G37s Sedan and it has Falken ZE912 tires on them. The front has 225/50/18 and I'm wondering if it's ok to buy 235/55/18 size tires for the front. Don't want to mess up the offset and speedometer. I found a pair for a good price and definitely want to buy it asap before it's gone.

Thanks for the help!

 

Don't do it, it's going to be 1.32" larger in diameter and 4.68% different than your current size. Use this calculator when trying new tire & wheel setups. For RWD try to be within 3% difference and AWD less than 1%.
https://www.myg37.com/forums/tire_rim_calculator.php

 

This^^ 100%!

 

I see, thanks for the help!

 

So for 235/50/18 it says Diameter 0.39" (1.45%)

That would be fine right? Thanks again

 

The calculator is great but as a quick reference to keep the same diameter go up 10mm in size and down 5mm in profile.

225/50/18
235/45/18

 

Not that simple, those two tires are off by quite a bit, over 2%.
and if you go another 10mm up and 5 down it's off by 4.4%
If you go up 30mm and down 5 in series you'll be pretty close though.
So a 225/50/18 & 255/45/18 will be close.

 

Guess I should have used the calculator myself lol. This was something I was told many years ago.