Best size wheels for 90-99 Mazda Miata? Suspension mods will be made.?

[Drew]

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)?

[Bahama121]

The newer Miatas have about 75 More HP at the wheels than the originals, hence it has the power to spin the larger 17" wheels. With the older models, they used a smaller wheel due to the low HP.



You will want to most likely go the 15" wheels. It will give you less unsprung weight than a heavy 16" wheel and give you more tire sizes than the 14" wheels.



A 16" or 17" wheel will add about 5lbs per corner affecting your handling in a bad way. Loss of acceleration will be noticeable as well, especially with 17's. A 14" wheel is a great choice, but you are going to be limited in High Performance tire sizes. This will also effect the cost of the tires as well. A 205/50-15 tire is sometimes more economical than the 185/60-14 which is a much taller and thinner tire.



If you want a good balance of lightweight, with a better choice of tire sizes and brands, I'd definitely stick with a 15".

[avgordguy]

If you really have to have bigger than 15s you need to go online to Miata net and visit the garage section so you can see what others did suspension wise to get the performance possible.  I have 15s on my 91 and it drives quite nicley.

[BrentB]

I have 15x6-1/2 Rota wheels with195-55-R15 Toyo tires on my 90 model, and they seem to be a very good compromise. The wheels are very light (I'm thinking 11.5 lbs, but am not absolutely sure). You can probably find a dealer on the web, and the wheels are manufactured in the Phillipines. The dealer that I bought mine from was Serious Automotive Accessories in Soquel, Calif. 413-473-1121 if they're still around,

[teameplerverizonnet]

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.