you should have keep it stock. The road in ATL here is rash too, but I was able to drop them. 1.5" is okay in your case. But remember, if your set of wheel + tires diameter is large = heavier, waste more gas and plus your speedometer will not be correct.

go here for tire size calculator:

http://www.miata.net/garage/tirecalc.html

and put your flame suit on :chuckles: