the logic is depreciation. if you sold your car at 7 it is worth a lot more than at 11. imagine buying a 1 year old cellphone and selling it at 2 years old. compare that to buying a brand new cellphone and keeping it 6 years. the depreciation is related to the markets expectations of the items functionality vs it needing expensive repairs. a 3-7 year old car generally is reliable and considered functional. obviously different brands and models differ on these curves. a 7 year old honda is very different from a maserati.