i'm thinking of trying 245/40/20's for my sedan but have used a wheel and tire calculator that suggested that you stay within 3% of a car's oem tire diameter because anything higher could cause brake failure while another website stated that anything under 5% is fine. i have 245/35/20's right now but i would like a little more sidewall.

 

This guy did. But IMO it looks too tall. 245/40R20 is the equivalent of a G with 22's as far as the overall diameter goes

https://g35driver.com/forums/v36-bra...els-tires.html