So I have an offer of $28k (end of lease buyout) for a used BMW i3-REx and started analysis: It turns out that 'mi/kWhr' is built into the car displays so: 746W (1 hp) assumed vehicle overhead based on Prius metrics. Needs to be measured. 18.7 kWhr usable pack capacity - rated at 22 kWhr but BMW specs show 18.7. EPA roll-down coefficients EPA lists the battery range as 72 miles, speed unknown It turns out, Edmunds has done a long-term study of the i3-Rex: 2014 BMW i3 Long-Term Road Test - Wrap-Up Resale and Depreciation: We purchased our i3 with range extender for $49,999. After one year and 10,400 miles, Edmunds' TMV® Calculator valued the BMW at $33,300 based on a minimal number of i3 sales available for comparison at the time. Given the tiny market for EVs in general, we weren't that surprised to find little interest in our used i3. Following a prolonged period on the market, we sold the car for the best price offered, a disappointing $26,000 from CarMax. Even after subtracting the $2,500 California rebate from the purchase price, our i3 still depreciated 45 percent. That's the worst ever for our long-term fleet, but it's slightly skewed by the fact that the i3 also qualifies the original purchaser for a $7,500 tax credit, a factor that doesn't enter into the equation. Bob Wilson ps. Why.