I have a question as well. I'm debating between a used Toyota Corolla or a used Prius....the Prius for the same year/mileage tends to be about $2000 more than a corolla....but the gas savings is significant. I'm not sure which way to go. If I get the Prius I'd likely go for one around $9,000 but that usually comes with well over 100K in miles...What do my fellow mustachians think?
So, my 2 cents because I have debating this a lot and trying to be pragmatic.
The Prius has an engine that is designed to engage/disengage frequently. It was literally designed for this purpose, while most cars are designed with the expectation that the engine will run continuously for a long period. There are other newer cars that have a similar design, but the 2008 Corolla was not designed this way. The result? Wear and tear on the car is very different. Short usage is not any worse for this car than long usage.
The car uses an electric motor for assist purposes and after 2010 can run entirely off of the battery for low speed driving.
The average "service life" of an electric motor is 30,000 hours. That is roughly the equivalent of 1 million miles. Toyota probably overdrives the motor, but most other car components are not designed for 30,000 hour lives. Result: The electric motor is also going to have less wear and tear than the ICE(Internal Combustion Engine)
The braking is regenerative. This means that each time you brake you essentially turn the electric motor into a generator. Once again, taking wear and tear off of the more failure prone devices.
Conclusion:
The Prius and any electric car should have longer service life than a similar ICE based car. This is generally confirmed by the service records on the Prius. As for my decision between a high-mileage car vs. an old car I have come to the conclusion that high-mileage is the way to go. The greatest destructive force on a high-mileage car is going to be the transmission, which isn't particularly taxed on a Prius. A life of 150,000 miles isn't abnormal on a transmission on a much more power engine, so I would feel safe saying that the 50/50 failure point on a Prius is closer to 200,000.
Your particular situation:
The one thing that MMM and life lessons in general has taught me is that we are not very pragmatic thinkers. We don't use logic, we use gut feelings.
Calculate your savings: 12,000 miles @ $3/gallon.
Prius: $800 per year for gas
Corolla: $1161
Imagine you were taking out a loan on this car. Not saying you would, but imagine it.
Corolla = $8,000 over 5 years at 3%. That is a payment of $143.75+$96.75 for gas=$240.50
Prius =$10,000 over 5 years at 3%. That is a payment of $179.69+$66.67 for gas = $246.35
You can calculate the break-even point for your own situation, but the point is that the fuel efficiency of the Prius is going to allow you to buy a roughly 20% more expensive Prius.
Now, what are you getting for your 20% higher payment? Old Prii do seem to retain their value slightly over other brands of cars. If you own it for more than 5 years you will start saving even more money.
One final thing, in my decision-making it allows me to take different routes. The Prius gets GREAT city mileage. I have the option of driving a route through city streets or driving on the highway. I currently favor the highway because it saves me money. The highway route is roughly equal in time, but it can be congested. The city street option? No traffic. However, because it involves about 2 dozen stop signs, it is rough on my old truck AND it costs me more to drive that route. I always favor the highway. In other words, a Prius for me will allow me to choose the route that I want rather than the route that is best for my vehicle.