You have a Miata that you are tracking or auto crossing and you want to go faster. The right wheels and tires will help get you there. Use what the pros use! Take a look at the Enkei Racing Series RPF1. The 17x7.5 wheel only weighs 15.2 lbs. By increasing thewheel size and reducing unsprung weight, your car will be quicker in acceleration, stop faster and the suspension does not have to work as hard.
Freedom Autosport is running these wheels on their Grand Am Continental Tire Challenge cars. In the street tuning class they ended up 4th in points last year overall. At a recent Mid-Ohio race I attended, the Miatas from Freedom Autosport ended up in 12th and 24th in the street tuning class.
If you want to run what a pro racing team uses, see which Enkei Racing Series wheels are available for your street car.