The original donut spares in both my 84 and 93 Daytonas are in great shape.
The full-size spare underneath my 92 Dakota had deteriorated enough by last year that I bought a new tire. People thought I was foolish to invest in a new tire, especially since I drive it about 3K to 4K miles a year, and don't have occasion to rotate them. But it's crazy to have a spare and for it to be non-functional. It's good insurance. And I winch it down at least once a year to be sure the winch works and I can actually get at it.
The full-size spare underneath my 92 Dakota had deteriorated enough by last year that I bought a new tire. People thought I was foolish to invest in a new tire, especially since I drive it about 3K to 4K miles a year, and don't have occasion to rotate them. But it's crazy to have a spare and for it to be non-functional. It's good insurance. And I winch it down at least once a year to be sure the winch works and I can actually get at it.