One more factor to consider: Your yearly mileage.
The higher your mileage per year, the following two factors apply:
- More mileage, more gas savings
- More mileage, the less you would be concerned about residual value
I will clarify number 2.
I drive over 30k miles per year. I drive my cars until they die. I don't expect any residual value whatsoever. If I get a donation deduction, it's a bonus. So if I drive a high residual value car into the ground, or a less than high, it still comes out to about zero.