Well that is what the ******* said... Looks like I need a talk with the dealership...

 

If you want. I'd just let it go. There isn't anything different they can do. Consider this; go to this web site:

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

Now if you plug in the stock 16" wheel tire size that the program is designed for, that would be 205/55r16. Now compare that to your actual tire. If you have a 225/40r18, you will find the difference is negligable. So your speedo will still be fine.

 

245/45/17's.