[donporfi]

I found that the deflated tire diameter of 15 and 16 inch tires is the same, so the tire that you are showing should have the same diameter and should fit in the trunck. Check both topics specially the second one.

http://forums.pelicanparts.com/porsche-911-technical-forum/357045-collapsible-spare-tire.html

http://forums.pelicanparts.com/porsche-911-technical-forum/176952-collapsable-spare-fuchs-2.html