on my Compact Jr I have 4-hole wheels with 175 70-R 13" tires
my spare is the same size.
but I like to carry two spares on long trips.
when you only have one spare and you have to use it then you are forced to go tire or repair shopping when it isn't always convenient.
someone in my neck of the woods has put on craigslist a never-used tire on a 4-hole wheel that has a 175 80 D 13" tire.
is that close enough to do short-term duty in a flat tire situation?