tires?

[mspeed03point5]

If my tires read 215/45 ZR 17 ............will a pair of 215/40 17's fit my wheels?

 

[Matthew]

should not be a problem.

 

[RyanJayG]

yeah, your spedo will only be off a little... no real issue.

 

[1Canuck2]

they'd fit, but the overall diameter would be smaller. The 45 and 40 part mean the height of the sidewall as a percentage of the width (which is the 215).

Thus, the tires are 215mm wide. The 215/45s are 96.75mm high, and the 215/40s are 86mm high, or roughly 1 cm less high.

The 17" is the part that tells you they fit a 17" wheel.

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

Speedo saying 60 would mean you are actually doing 57.9, or 3.4% difference.