Comment 80 years (Score 0) 429
Age is not the main factor, can it still do what it was designed to do, safely, is the question. I mow my grass with an 8-N Ford tractor (around 1949), nearly all small farms keep one around for odd jobs; not 80 years yet, but will still be running fine when it is. Ford didn't design them to last forever, but with modern oils they probably will.