Hard drive POH

if, hypothetically, I have a hard drive with 1660 days of power on hours, is it time to start thinking of replacing it?

4.5 years? I'd say so, if it's your primary drive. If it's a data drive... Eh. I'd say if you feel it should be, replace it. But if it's your primary/boot drive, I'd say replace it.

Iit's an old dell, so mebbe.....