ACE educators get this question more often than you would think. I’ve also been asked by students, “Do you drive a Prius?”

So what’s so special about the Prius?

The Toyota Prius, it is one example of a gas-electric hybrid (all hybrids have more than one energy source, but they are not all gas-electric). The Prius combines an electric motor and sophisticated battery with a basic gasoline engine that ultimately saves money and the environment by being more fuel efficient. The Prius is touted by Toyota and other car enthusiasts as one of the ultimate ways to become more green.

I tend to start my answer to the Prius question by saying that I would spend more time researching bike routes and other alternative transportation vs. researching which new car to buy. Ideally, any car you buy is worse for the environment than biking, walking, busing or riding  with a friend. 

But, if you are in the market for a car, let’s get the skinny on the Prius:

I while back heard about an article comparing a Hummer to a Prius saying that the Hummer was actually more energy efficient if you examine the life-cycle of both cars. Even with the high cost of production, I’ve always been skeptical about this assertion. As any savvy environmentalist knows, the true environmental cost of a product doesn’t just start and end with its utility. They consider the manufacture, use and disposal to find a product’s real environmental impact.

Much of the controversy regarding the cost/benefit question of the Prius that centers around nickel-metal hydride battery and the life-cycle cost of a hybrid and came out of an article entitled “Dust to Dust” by the CNW Marketing Research Group in 2006.

The article claims that the energy put into the development of the nickel-metal hydride battery increases the life-cycle cost to well above that of a Hummer. They also claimed that the manufacture of these batteries causes environmental damage to the area around the manufacturing plant.

The way they describe it, it sounds like the Prius is the farthest thing from being environmentally friendly.

Knowing that many popular skeptic arguments sound good but often cherry pick data to support their claims, I knew I needed to do more research to get to the bottom of this debate.

I began with an article by Dr. Peter H. Gleick from the Pacific Institute who exposed the article for its faulty science methods including creating statistics for the hybrid that had no specific reference. They also used photos of the manufacturing site that were taken during a time other than when the plant was manufacturing the batteries. The authors later amended their original findings (although this rarely makes popular media compared to the initial articles).

My own research uncovered this statement by the U.S. Department of Energy’s Argonne National Laboratory, “If you drive both a conventional and hybrid car for 160,000 miles (257,495 kilometers), the conventional vehicle requires far more energy to operate and emits far more greenhouse gases over its lifetime, significantly canceling out any imbalance during the production stage.”

With regard to the disposal issue of the battery, the manufacturers claim the battery will last the life of the car which should make disposal on the whole better than conventional batteries that must be changed out more often and contain lead (although hybrids haven’t been around long enough to be able to test this theory).

According to the Toyota Prius web site, the car gets 51 mpg city and 48 mpg highway. My perusal of the site Prius Chat (who knew) revealed actual car owners claiming that they got anywhere from 46.3-59.4 mpg in a combination of city and highway driving. Compared to my 2003 Subaru and the current cost of gas in Colorado, I’m becoming more convinced.  http://images.automotive.com/reviews/images/03-forester-hero.jpg

To sum it all up, David Friedman, the research director at the Union of Concerned Scientists in their Clean Vehicles Program says, “The reality is hybrids can significantly cut global warming pollution, reduce energy use, and save drivers thousands at the pump.

My answer to the question, even with all of the research, I’m going to hang on to my 2003 Subaru for the long drives and stick to the bike paths of Boulder, Colorado for 90% of my transportation needs.