Should I replace 10-year old spare with a used tire?

[theblue]

I think you'd be crazy to replace it unless it's dry rotted or has some other defect.

It just lived the last decade in a nice dark, air conditioned place, it's probably as good as any new tire.

last year I had to use the spare tire from in my 97' 328 and it worked great and without issue. It even still smelled new.