Originally Posted by Volk Z

The only flip side of a 19 vs 18 is a smaller sidewall which means less flex around a corner, which in turn would aid in track times... BUT that being said an 18 on the 370z would still use a 35-40 series profile which is still low.

For drag racing a higher sidewall in the rear may help off the line.

Overall an 18 inch would typically be lighter using the same rim comparison but a Volk CE28 in a 19 inch weighs around 19-20 pounds vs a Rota knock off weight more in an 18 inch. So this comparison must be 18 vs 19 in the same exact wheel and same tire brand combo and width.

Handling can be tweaked with the slightest adjustments like alignment, tire pressure etc.

The only real way to test if you are that specific to getting the lowest track times is testing. We all know they didn't just slap the GTR together and go "I bet she goes fast"... NOpe they continually tested at the Nurbergring track over and over and made tweaks.

-Chad