theaveng said:
30mpg? These base econo cars get 38-45 mpg. If I redo your calculation I come-up with over 1 million miles I would have to drive a Prius to match the $13,000 savings of a Mitsubishi Mirage.
Maybe if you never take the car off the freeway. The dirty little secret with those shitty econo boxes is the city mileage, which is generally terrible. Take the Chevy Cruze Eco, the highway mileage king right now, non-hybrid. It gets 42! on the freeway! And that's the number you'll see in every ad, which makes you think it's just a notch below the Prius at 50. But it gets 28 in the city. So, you better not drive it off the highway much, or you'll be seeing about half the mileage you'd get from a Prius.
And you should be happy I ran with your $10000 number. The Prius MSRP is 24,200. The comparable trim Corolla (with cruise control and all the other things that the Prius includes on the "Two" model) costs $18,300. That's $5900. And that's comparing it to a compact car. The Prius is a midsize, so you should probably compare it to the Camry, which starts at $22,500. But I'll be nice, and assume that the less space available in the Corolla doesn't matter.
So, let's do it again, with combined 35 for the Cruze and 51 for the Prius with a $5900 break even. That's still about 180000 miles. I'm pretty sure Priuses last about twice that long, at least. And the Prius is much larger than the Cruze.
Now, if you spend 90+% of your driving on the freeway, then it doesn't add up. You get over 300000 miles. Though, with that much freeway driving, that car may make it to a million miles, so it probably still makes sense.