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

Well amount of Energy != Green

[jellomizer]

The question is what type of eneregy is used, and how much is producted from the energy source. Automobiles are a lot more energy effecient then say a human. But they give off polution that is less "green" or more difficult for the environment to handel.

not the CNW BS again.

[CapsaicinBoy]

Oh man, How many times do we need to go over the flawed assumptions and conclusions from the CNW Marketing analysis.

First, it incorrectly assumes that hybrid batteries are not recycled. In reality, Toyota has very successful recycling program, including a $200 bounty on Prius batteries.

Second, it is interesting that TFA mentions the Scion xB. Yet it fails to note that the CNW report data on the xA and xB don't make any sense. They are built on the same assembly line, have the same powertrains, only differ in weight by 50 lbs or so, and have similar efficiency (~35mpg), yet the CNW study shows the lifetime energy use of these vehicles to differ by 50 percent. How's that work?

Third, the CNW report makes really bad assumptions about where the bulk of lifecycle energy use occurs (eg manufacturing vs operation).

In short, it's misinformed at best and is more likely an intentional greenwash to assuage SUV owner dissonance in a post 9/11 world.

Disclaimer: I drive a biodiesel powered Jetta TDI, not a hybrid.

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.

Calculated Prius cost

[SheldonLinker]

I have a Prius with 46,000 miles it. I average 52MPG. Gas costs $3.13 today. Here are my total costs:

Purchase: $26,000 or so. That's 56.5 per mile.
Gas: 6 per mile.
Oil: 0.5 per mile.
Tires: 1 per mile.

TOTAL: 64 per mile, so far.

If I threw the thing away today, and bought a new one (which I'm not likely to do, so don't check my dumpster), that would still be 64 per mile. Assuming it will last 250,000 miles, like the rest of my Toyotas, the cost will be WAY lower.

Re:Not even close?

[crunch_ca]

And then the next 120 pages are disclosures, articles, correspondance, photos of cars, editorial cartoons and song lyrics. I am NOT joking.

I was dubious. However, I actually read the source material. The guy is a crackpot.

Appendix B: An invitation to drive a XEBRA electric car
Appendix E: Some spam about a psychology professor and techniques for memorization.
Appendix UU: Cartoons
Appendix BBB: The lyrics to 90 Pounds SUV

There's more common sense at the Time Cube