Monday, June 22, 2009

Eco-nomics: Should I Buy a Prius?

My wife recently suggested that, with my frequent commuting to Corvallis and the excellent mileage of the new 2010 Prius, I should consider purchasing one.

At roughly 50 MPG on average it seems to make a lot of sense. But I have a pretty good car already, my Saab averages over 30 MPG in all of my driving which combines a lot highway and a fair amount of city. [This is a lot better than it is supposed to according to the EPA estimate, not sure why]

So here is the thing, assuming I drive 15,000 miles a year (this is high, but for argument's sake...) I will save about 200 gallons of gas.  So, at $4 a gallon this saves me about $800 a year.  Add another $1 for the cost of my carbon consumption (reasonable figure according to some estimates) and the total comes to $1000 a year.  This is considerable, but not as good as you might think given the additional 20 miles on a gallon of gas I gain.

And thus I run into an error of logic that a lot of people have been talking about recently: going by the MPG numbers gives you a distorted sense of the benefits of fuel efficiency.  To see this, consider if I  had a car that got 15 MPG and switched to a very modestly better car that got 20MPG.  Over the same 15,000 a year, I would save 250 gallons of gas!  

The moral is that all the people that trade in their reasonably efficient car for a Prius, don't do nearly as much to reduce carbon emissions as a person who went from a Suburban to a regular sized SUV - or to a Prius.  [Of course this doesn't factor in the secondary market in which poor fuel economy cars are becoming incredibly cheap - encouraging people to buy them]

It doesn't meant that I shouldn't buy a Prius and when I my current car wears out, I will look to find a fuel efficient alternative, but in a few years I hope to have even better options.


Anonymous said...

If you're a car enthusiast and care about steering feel, handling, brake feel, and like to shift, you'll definitely enjoy your Saab more than a Prius.

Actually the Honda Insight does better at all these things and costs less too. See Car and Driver's "Mileage Maestros". The 2010 Prius beat out a 1998 Chevy Metro, but was bested by the 2010 Honda Insight (this test was more than just a simple comparison of fuel economy).

Stacy said...

Buy a Prius... and then watch all of your savings disappear in 8 or 10 years when the lithium-ion batteries wear out and have to be replaced.

Ask the Bolivians how they feel about lithium mining.

The real issue is how comfortable you want your commute vs how serious you are about saving money.

Buy a motorcycle. Let's say a Ninja 250, which will get 80 mpg on the freeway easily. That kind of efficiency makes the Prius look like a Hummer -- plus it's a fun little bike to ride.

However, if you're not a die-hard rider (and most riders in Oregon are not), you'll only ride it in good weather, which negates much of the savings.

So... plush commute? Or... saving money?

Becky Davies said...

Is it possible that buying a used car with less than 50mpg is environmentally superior to buying a new Prius altogether? In other words, potentially at some point the energy/material cost of producing a brand new car as compared to purchasing a used car could outweigh the benefits of the high mileage. I imagine there is some mpg-gained breaking point.

Jeff Alworth said...

Nice comments. I would be interested to hear the calculation on Becky's suggestion about a used car. (Assuming, say, a high-MPG, low-mileage car.)

I think of these questions slightly differently, though. Let's assume we could select a car that did in fact have a lower carbon footprint, including factors like carbon produced during production, added footprint due to lithium mining, and end-user emissions. Then we discover that the benefit for such a car is marginal--let's take your 200 saved gallons as an example. Is it really worth it?

The answer is that if every new-car purchaser improved their footprint by 200 gallons a year, it would be an amazing benefit in the aggregate. When you multiply small actions, you get big results. Climate scientists believe the only effective way to step back from global warming is through a series of "wedges"--small steps in a range of activities that in the aggregate begin to edge us off the precipice. The same can be said for individuals: we have to make our marginal contributions.

Not to say you should buy a Prius--maybe you should wait and buy a Volt. But your question was the larger mental frame, and I would say that marginal gains are critical in global warming.

spencer said...

Why would you want a Prius? Why not look into a turbo diesel vehicle? The technology has been developed in ways you could not even imagine in the last 5 years. The on;y problem is that the TDI's are in high demand.

The 2005 Jetta TDI would be more fun to drive, a looker compared to the trendy yet ugly Prius, and you can get between 40 to 50 mpg. Buy used and save the planet. I personally have had road trips averaging over 50mpg using proven driving techniques. I have seen some guys re-gear the transmission and get 60mpg and yes they are only running one battery.

A Prius has to be quite a status symbol in the staff parking lot these days.

If you want electric wait for the Tesla. The Volt is a figment of United States Motors imagination.

Oliver said...
This comment has been removed by the author.
Oliver said...

I second Spencer. My wife and I just drove a 2003 TDI VW Beetle on a road trip to Yellowstone and averaged 60 mpg. Plus, you don't have to pay dealership prices for standard maintenance.

Navy Dad said...

Have you seen the Oregon Hybrid/PHEV tax credit for its residents?

When the warranty runs out you can may want to purchase a Hymotion for your Prius.

Or see how others convert their Prius into a Plug-in Hybrid Electric Vehicle (PHEV)

Toyota provides an 8 year 100,00 mile battery warranty and read their article about battery costs.

Motorcycle? I don't want to end up as road kill.

Anonymous said...

its a good decision i like your thought ,,,
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