Well I've finally had enough with the constant trips to Discount to get these things re-balanced. The last straw came this morning (actually Sat. when I took them to get rotated and balanced and they left out the balance part) when I went in to have them rebalanced. They just cannot seem to get these things balanced. Well, I got online with national customer service and talked to one of their reps, he said that the Kumho's should've never been reccommneded for this car anyway. He told me to call national customer service, so I did. He suggested I call the store and that if I had any problems getting them replaced, call him back. So I call my local shop and they said they'd pro-rate the value on them (which is going to be over 90% cause I've had them all of 6K miles) and get me a new set. I ended up choosing Pirelli P Zero Nero M+S in 225/50/16 size.

The interesting part came when I called my S.A. at the dealer and told him what I was going to do. He said to go back to stock size 205/55/16, but I plugged in the numbers into Discount's tire calc., and also into one from a Miata site that I got a link to from here by using the good old search button, and found some interesting results that has pushed me to keep on with the 225/50/16's. The difference between the stock size and the siz I am going with is SO miniscule. The only big difference is the tread width is significantly wider than the stock size tire. Everything else is minute. Check it out:

The differences are as such
Sidewall Height: .1
Section Width: .79
Overall Diameter: -.2
Circumference: -.7
Revs per mile: .68


The miata calc. found no difference at all. Now the dealer has said that it's the mass of the tire (too heavy) that's causeing the problem (215/50/16 vs stock 205.55.16) and that my suspension can't handle it, but with this little difference between the stock tire size and the 225/50/16's that I've ordered, I don't think I should have the same problem with these as I am currently having with the Kumho's. What do y'all think?