my spare on my 61 is at east 20 years old. in fact I had to have the ri replaced because it had rusted away. the guy at the tire store told me that the rim was shot but when he inspected the tire it was functional. he said that it would be bad to use it as a primary tire, but it holds air and is not rotted so it is a suitable spare. i guess the point is that old does not mean unusable, but don't go overboard. i would rather have new tires under a truck than new old tires. maybe its just me but something feels safe and secure about my brand new tires.
