Spare Tire - Donut for Upgraded Tire Size

[GRONK]

So, I am running 205 75 15's.  I still have the factory spare w/ the original tools in the trunk area and was wanting a properly sized spare.  I still want it to fit in the factory location under the rear deck/through the hatch. 

I did the math and a 205 15 75 has a circumference of 85.1".  Definitely larger than the factory spare.  I did a little more math (almost ran out of fingers and toes) and found that a 145 80 18 has a circumference of 85.2".   It just so happens that a  newer VW Tiguan has a 5 lug factory spare 145 80 18.  The lug pattern is "slightly" different.  It measures 112mm, where the Eagle measures 114.3mm.  I'm thinking for an emergency spare, it should work just fine.  I ordered the wheel and I will update the post.  I just don't want a full sized spare mounted to the roof rack on road trips.  If the fit in the trunk is tight, I will deflate the spare until it fits (I have the factory onboard air pump under the hood)  If I have to, I will slightly mod the lug holes, as an emergency spare, it isn't bothering me "yet"

Anyone else do something similar?

[vangremlin]

This is the first time I've seen anybody put this much thought into the spare tire for an Eagle 

Good luck and let us know how it turns out.  I'm thinking you may run into problems trying to get that VW bolt pattern to match up.  You may be able to find an 18" wheel with the proper bolt pattern and swap the VW tire onto it??

You may also want to carry a can of fix a flat and never have to use the spare.

[GRONK]

I don't have a spare in any of my vehicles, but always try to keep one in the wife and kiddos' vehicles.  A little CMA in case they ever get stuck on the side of the road.  If the wheel lug pattern doesn't fit, I will source a proper wheel.  If it does work, I solved a problem someone doesn't know they have 

[vangremlin]

Let us know how it turns out!

[eaglefreek]

As long as you don't go into 4wd, a different size spare will work just fine to get the car off the side of the road and to the tire shop to repair the damaged tire.