With that rim combo, your speedometer (and odometer) will read 3.2% too slow, at 60mph indicated you will actually be going 61.9mph.

If you can get something in 195/55R15, that would be ideal, even though it's still kinda narrow.

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

It all depends how far off you don't mind being. Right now I am running 215/55R16's on a car designed for 205/60R15's. In other words, my speedo/odo is 2.5% too slow.