I hate the idea of having the incorrect diameter tire for the spare, especially when most other countries get a spare that has the correct diameter. Australia, Mexico, and most of Europe get a 185/80R17, which is still a temporary use spare, but it has an outside diameter of 28.7", which is exactly the same as the factory 225/55R19 (the 17" tires are 28.5" which is basically the same thing). In the US, we are given a tiny 145/90/16, which has an outside diameter of 26.3". A difference of 2.4". This small spare will go 68 more revolutions per mile than the stock tires when in use, which would be more important to AWD owners, but I think could also create problems for FWD if you have to put it on the front. Plus it is so damn skinny I don't trust how long this thing could actually hold up if you needed it to. I'm sure Mazda did this to save the 11.6 LB weight difference, but how much fuel can that save really?
You can't get the 185/70R17 tire available in other countries anywhere in the US. I tried a lot of places and you can't. But I did find a 165/90R17 from Tire Rack that also has the perfect diameter of 28.7". This picture shows the factory tire, the new spare from Tire Rack, and the original spare for comparison. Which spare would you rather use if you were in the middle of nowhere?
-snip-
Parts needed:
17" X 5.5" steel wheel from Med Center Mazda
https://www.shopmazdaparts.com/oem-...re-9965025570/?c=aT01NDY1MTcwNSZyPWxheWVyXzE= $119.31
T165/90R17 Kumho T121 from Tire Rack
https://www.tirerack.com/tires/tire...m=69R7KH&vehicleSearch=false&fromCompare1=yes $79.10
Weight of original spare and tire 24.4 LB. Weight of new spare and wheel 36.0 LB.
You can also use a true factory aluminum wheel and full size tire and it will fit diameter-wise, but the thickness will raise the floor level about 2.5".