I'm looking into Miatas and was wondering, what is the best choice for wheel size when upgrading from stock? The new Miatas have 17", but the suspension may be tuned differently for the larger wheels.
I'm looking to get anywhere from 90-99. I want to go 16" which is larger than stock 14 or 15s. But I want to know if this will work well with Koni shocks and Flying Miata Spring (or similar)?
The new miata's (I think) run what are called + sizes.
The OD of the tire remains the same while the wheel size increases. So lets say that you go from a 14 to a 15 inch rim and buy the + tire. You decrease side wall flex, which in turn helps to keep the tread flat on the road. But because the side wall flex has been reduced, the ride is rougher.
It you increase the OD of the tire you are in for some major handling problems. You would have to adjust the off set of the tires in such a way as to have the center line of the tire at the road be at the same point as an imaginary line through the upper and lower ball joints on the spindle.
As long as you do not change the offset, or tire OD, +, ++, +++ rim and tire combo's will work fine.
See Mazda Miata Performance Handbook (Garret Publishing) written by Norman H. Garrett III.