Originally Posted by JetBlack5OC
But of course this doesn't apply to the 20's on the GT-R. Because it is big, special, and was designed for 20's. The magic electronics and suspension on the car just eliminate inertia from the equation. I am surprised Nissan hasn't figured out how to eliminate the force a gravity while they are at it. Fact is Nissan picked 20's for the GT-R.
Sarcasm will not make up for you seeming lack of understanding. Of course it applies. I is I is I, period. The OEM choice of a tire wheel size combination is one subject to a great many variables and compromises. If you could replace the wheels on the GT-R with wheels that have a smaller I it would perform better, period, no if's and's or but's. BUT given the gearing, brake sizes, existing suspension design, etc. you (almost for sure) can't find 19s that will work on the car. If you could you'd likely have tires with sidewalls too flexible for the suspension. I suspect brake rotor diameter is actually the key limiting factor though. The brakes are a huge 15".
What is "best" for the GT-R is clearly NOT best for the M3, why is that so hard to understand?