bigger alloys

[skodave69]

will changing my alloys from 16inch to 18inch affect my speedo? e.g would i end up over the speed limit?

[Toureman]

Yes.

No, under it.

[Panic Button]

Depends on the size of the tyres.

If they are low profile so the circumference of the wheel is the same, then it will have no effect.

[donn1901]

The speed will differ slightly but not a great amount. Just make sure you stay in the speed limits and the 10% calibration the law allow you on the speedo won't trigger off a camera.

[oldhamfan]

Try this site, it should make it clearer for you:

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