Thanks for your question Andrew.

The tables are from Edmunds.com, without alteration. The adjustments (removing the finance charges from Years 6–10 for the case where you keep the car you bought new for the 10 years, plus the interpolation of the Year 6 depreciation) are done by hand and are mentioned here:

“Buying a 5-year-old CRV and keeping it for 5 years would cost $32,085. However, if we remove the financing cost and adjust the year-1 depreciation as described above, we arrive at $28,443.”

The reason for the interpolation is that there is no reason to expect the depreciation to be $2195 in Year 5, jump to $2992 in Year 6, and then drop to $1329 in Year 7 if you bought the car new and keep driving it for 10 years.

My hypothesis is that the second CRV table, which is for buying the car used when it’s 5 years old, assumes that many people buy their used cars from dealers, who mark up used cars above their market price. Then, if you turn around and sell the car, it will have lost not just the typical annual depreciation, but also the dealer markup.

To avoid this irrelevant-for-our-case markup effect, I interpolate between Year 5 and Year 7.

Makes sense?