“FWIW, I did a back of the Excel trade study, assuming 15,000 miles driving a year and a 10 year economic life, cost of money at 6%, comparing the Prius and Corolla. The break-even point is gasoline at $6.00 per gallon. “
That’s about right since a Toyota Corolla, which is a better driving car than a Prius, can be had for $7,000 less than a Prius. That’s a lot of gas (about 75,000 miles).
Prius = 58 city / 53 highway
Corolla = 30 city / 42 highway
Say even balance of both, 50.5 mpg Prius, 36 mpg Corolla.
Gasoline consumption per 150,000 miles (ten year life) is 2970 gallons for the Prius, 4267 for the Corolla, a difference of 1196 (say 1200 gallons). If the price of the Prius is 7000 more, gas would have to be 7000/1200 = $5.83 dollar per gallon to break even. This ignores the price of money, which favors the Corolla, because Prius is upfront money.
If I assign a cost of money to the $7000 up front cost at 6% per year, the price of gas would have $7.92 per gallon to break even. YMMV.
Some people prefer the Prius. Good for them.