hey i got 205/65/15 right now on my 88 gxl...
would I mess up my speedometer by putting on 205/45/15?
i want a shorter sidewall for better turning and looks..

thanx a head of time

 

Stock tire size is 205/60x15, so there're already one size too tall. Going to 45s would be far too small. You can't make big changes in profile without changing rim size. Your speedo would read high by about 10% (currently about 3% too low, no biggie) and the whole thing would look funny because the overall diameter would be so much smaller than stock. You eally need 17" rims to run 45 profile tires.

 

www.miata.net/garage/tirecalc.html

 

Thanx for the answers one more question
what offset are out rims?
so if i wanted to get some 17" what offset would i have to request?