How old can a turkey vulture get?

Your question is not specific enough for us to answer because Vulture is the name given to two groups of covergently evolved carrion eating birds in both the New (7 species) and Old (16 species) world. Vultures are found on every continent except Australia and Antarctica.

Thus, as you can see, in order for us to even begin trying to provide you with an answer you would have to define which species of Vulture you wanted the average age for. I would also expect that the data required to provide this information may be a bit scant.