Hummer Greener Than Prius?

An anonymous reader sends in a story from Central Connecticut State University, claiming that a Prius takes more energy to manufacture than a Hummer — 50% more. In addition, the article claims that the Prius costs $3.25 per mile over its expected lifespan of 100,000 miles compared to $1.95 per mile for the Hummer. The article gets its data from a study by CNW Marketing called Dust to Dust, which is an attempt to account for all the costs of vehicles, from manufacture through operation through repair and disposal. The $3.25/mile cost quoted for the Prius is the 2005 number; for 2006 it is $2.87. This improvement pulled the Prius below the straight industry average — all the other hybrids are still above that average. And the Hummer is not listed at all for 2006. Update: 03/21 00:44 GMT by J : You might want to take those figures with a grain of salt; I don't think anyone's seen the supporting data. Read on for details.

J adds:

The Prius's mediocre cost-per-mile is due mainly to CNW Research assigning the car a short expected lifetime: 109,000 miles. Nobody knows where this number comes from because CNW has not published details about its derivation. If a car will not last very long, then of course its energy cost per mile is high.

Back in July 2006, when CNW's study "Dust to Dust" had just been published (and which remains, unchanged, the original source for today's news), I emailed its president, Art Spinella:

Hello,

I'm with the tech news and discussion site Slashdot.org. One of our readers submitted a story about your Dust to Dust study.

According to Wikipedia, the Prius comes with a 150,000 mile warranty in California and a few other states; 100,000 elsewhere.

On p. 21 and p. 40 of your report I see that you estimate the average Prius will be "removed from the streets... and sent for disposal" at 109,000 miles. Can you explain how you arrived at this figure?

Thank you.

I did not receive a reply.

My question was about the cost-per-mile denominator; here's another critique questioning the numerator.

Comments

Impossible Numbers

[diakka]

TFA claims that the prius costs $3.25 per mile over the course of 100,000 miles. The car must therefore cost $325,000 to own over the lifetime of the car. That sounds pretty impossible to me. I think somebody miscounted a zero when they were doing the math.

Re:wtf?

[jimmyfergus]

The Prius was never for real environmentalists anyway. It's for lazy yuppies who want to put out an environmentally conscious image.

I came to that conclusion when I did a calculation of the energy saved by turning off my computer when I wasn't at work. It's amazing how many people leave them on all night to save minor hassle (I know sometimes there good reasons, but not for most cases where I see it).

I worked out turning my one work computer off as I leave the office keeps about 1 ton of CO2 per year out of the atmosphere (workings below), plus an amount of mercury and other pollution, assuming the electricity here comes from coal. It takes 100 gallons of gasoline to produce 1 ton of CO2. Please correct me if I'm wrong

• My machine: a twin Xeon, draws 140W at idle. More efficient machines may draw little more than half of that. Laptops, significantly less again.
• If it's off 15 hours at night and all weekend: 123 hours
• Coal generation produces about 2.3lb CO2 per KW/h (reference)

0.140 * 123 * 52 * 2.3 = 2059lb

• CO2 per gallon of gasoline: ~19.4lb (reference)

therefore 2059 lb is produced by around 106 gallons of gasoline.

That's about how much I'd save if I had a Prius (I do ~8000 miles/year). Sure, many people do more, and have more efficient computers, but it puts it in perspective.