I know that M.T.'s have a date code on them, but I don't know if other brands do or not. I will run a new set for 2 seasons, after that I will sell them pretty cheap. No matter how much tread is left on them, the rubber has gotten too hard to hook properly. I would pass on the 5 year old pair. They sell a product that is supposed to soften the rubber back up, but I've never tried it.