Prius v. Hummer

"If a man is offered a fact which goes against his instincts, he will scrutinize it closely, and unless the evidence is overwhelming, he will refuse to believe it. If, on the other hand, he is offered something which affords a reason for acting in accordance to his instincts, he will accept it even on the slightest evidence. The origin of myths is explained in this way."
- Bertrand Russell

An average sedan consumes about 10 liters of petrol per 100km traveled. A small car does about 7 liters. The Toyota Prius hybrid car, however, has a rated fuel efficiency of 4.4 liters per 100km. Even though it has low fuel consumption, the Prius in Australia is priced at $37,000. This means that it is about double the price of a Yaris. The Prius then is not exactly a mainstream car like the Corolla is. Research by J.D. Power shows that the average Prius buyer's income is over $100,000 and this suggests an intention by Toyota to sell the car as a environmental status symbol for the wealthy.

The Prius has been popular among celebrities. Titanic star Leonardo Di Caprio says, "I own a Toyota Prius; it's a step in the right direction. It's a gasoline-electric midsize car that gets about 50 miles per gallon. We have the technology to make every car produced in America today just as clean, cheap and efficient." Cameron Diaz says, "It gets 52 miles per gallon. In the city. Isn't that exciting?" Other celebrity Prius drivers include Alicia Silverstone, Billy Crystal, Billy Joel, Brad Pitt, David Duchovny, Ellen DeGeneres, Ewan McGregor, Harrison Ford, Jack Black, Jack Nicholson, Larry David, Kevin Bacon, Kirk Douglas, Kurt Russell, Patricia Arquette, Prince Charles, Robin Williams, Salma Hayek, Susan Sarandon, Tim Robbins, Ted Danson, Tom Hanks, and Woody Harrelson.

Some time ago, a study by CNW Marketing Research claimed that the Toyota Prius hybrid car is more environmentally harmful than the Hummer SUV. The study claims that the Prius only lasts for about 100,000 miles whereas the apparently more durable Hummer lasts over 300,000 miles, meaning its environmental costs are spread out more over its lifetime.

According to the study, the Prius costs an average of $3.25 per mile driven over a lifetime of 100,000 miles while the Hummer costs $1.95 per mile to put on the road over an expected lifetime of 300,000 miles.

This is all very perplexing because I remember reading a paper in which Toyota expects the batteries to last the life of the car and to date not one battery has been replaced.

"Toyota claims that not one has required a battery replacement due to malfunction or 'wearing out.' The only replacement batteries sold--at the retail price of $3000--have been for cars that were involved in accidents. Toyota further claims that the nickel-metal hydride (NiMH) battery packs used in all Prius models are expected to last the life of the car with very little to no degradation in power capability.

"According to Toyota, the life of the Prius battery pack is determined more by mileage than by time, and it has been tested to 180,000 miles. Supporting this are first- and second-generation Prius taxis in Canada that have reportedly traveled more than 200,000 miles without suffering any battery problems."

Source: http://consumerguideauto.howstuffworks.com/...


"Toyota have lab data showing the Prius battery can do 290,000km of normal driving with absolutely no degradation of the battery’s performance. To give some real life examples, there is a Taxi driver from British Columbia, Jatinder Parhar, who has done over 410,000km in his Prius Taxi and has had to do nothing to his Prius other than standard servicing. Toyota has sold over 500,000 Generation II and III Prius worldwide and say they have never had to supply a battery pack for replacement due to wear and tear. Given all this, the price of a replacement battery is probably irrelevant, however in the extremely unlikely event you needed to replace the battery in your Prius, current cost, at time of writing (Oct 2006), is NZ$3900.00 for a Generation II Prius and NZ$2700 for a Generation III Prius. However this is coming down all the time."

Source: http://www.cleangreencar.co.nz/page/faq-prius


So of course we'll just have to wait and see whether some taxi can clock more than 300,000 miles. The Prius taxi in Canada has done 410,000km, which is 254,901 miles.

The CNW Marketing study stated that the Prius costs an average of $3.25 per mile driven over a lifetime of 100,000 miles and the Hummer costed $1.95 per mile to put on the road over an expected lifetime of 300,000 miles. Assuming that the Prius taxi with over 200,000 miles on the odometer was not an anomaly and that its results are representative, then the initial reported cost of the Prius of $3.25 per mile assuming 100,000 expected lifespan would now be $1.63 per mile assuming the Prius can last till 200,000 miles (which it has done). At $1.63 the Prius is better environmentally than the Hummer. However, if the Hummer lasts longer than 300,000 miles then the results change.

As I said, the study that claims Hummers were greener than Priuses was done by CNW Marketing Research. The study did not have any peer review and had no support from mainstream scientific papers. The results of the CNW Marketing Research firm contradict data from MIT and the Argonne National Laboratory (see the Pacific Institute paper).

According to Gleick from the Pacific Institute, "A quick re-analysis with peer-reviewed data leads to completely opposite conclusions: the life-cycle energy requirements of hybrids and smaller cars are far lower than Hummers and other large SUVs."

The CNW study provides no explanation for where they got the assumption that the Prius only lasts for 100,000 miles, so it could be that they just plucked it out of the air or, if you are cynical, selected it to artificially skew the results and conclusions.

The Prius taxi in Canada clocked 410,000km, but I don't know anyone who drives a car until 410,000km. When the RACV does analysis on car operating costs they use 15,000km per year as the number of kilometers done by the average driver. So if we assume that the Prius taxi in Canada is representative of all Priuses then a Prius should last you over 27 years (=410000/15000).

Some people, like Jeremy Clarkson, claim that diesel is better than hybrid. But according to HybridCars.com it is not an either-or situation: "It's technically possible to use a hybrid drivetrain with a diesel engine. In fact, PSA Peugeot Citroën recently showed a diesel-hybrid prototype: the 307 CC Hybride HDi, a compact convertible that gets 70 miles per gallon, about 30 percent better fuel economy than the existing diesel version."

A diesel hybrid truck has been made by Hino and will be available in Australia.

While a diesel's fuel economy is similar to that of hybrids, there are health worries associated with diesel. Studies into pre-1990 diesel engines have found a link between diesel emissions and cancer. Modern diesel engines, however, are cleaner but more stringent regulation from the US EPA means many diesel-engined cars will be banned in the US and maybe other governments will pass similar laws in an effort to improve air quality.


Further Reading:

• The Anti-Hybrid "Dust-to-Dust" Cost Study that Just Won't Die, But Needs To
• Prius Versus Hummer: Exploding the Myth
• Oh, So a Hummer is Not Greener than a Prius
• George Will Promotes a Denialist Report
• Hollywood Loves Hybrid Cars
  

More on the Prius Taxi:
Cab Driver Passes 400,000km Mark in Prius
Hybrid taxi paid for itself in no time