It’s easy to focus exclusively on gas mileage when making an environmentally conscious car choice. But there’s more to the story.

CNW Marketing Research Inc., an Oregon-based auto research spent two years collecting data on the energy necessary to plan, build, sell, drive and dispose of a vehicle from initial concept to scrappage. They call it a dust-to-dust analysis of the environmental impact of a car.

You may be surprised if you thought hybrids were the obvious winners.

The Honda Accord Hybrid has an Energy Cost per Mile of $3.29 while the conventional Honda Accord is $2.18. Put simply, over the “Dust to Dust” lifetime of the Accord Hybrid, it will require about 50 percent more energy than the non-hybrid version, CNW claims.

And you may do a doubletake after reading this:

For example, while the industry average of all vehicles sold in the U.S. in 2005 was $2.28 cents per mile, the Hummer H3 (among most SUVs) was only $1.949 cents per mile. That figure is also lower than all currently offered hybrids and Honda Civics at $2.42 per mile.

Basically, when considering all relevant variables such as materials, fabrication, plastics, carpets, chemicals, shipping, and transportation, gas mileage turns out to be significantly less relevant than many people assume.

What I like about this study – and of course it’s just one study – is that it looks at the total cost/impact of creation, ownership, and disposal. It’s easy for the media, the public, car dealers, and car manufactures to focus almost exclusively on miles per gallon. However, as is usually the case, reality points in a different direction than what’s convenient.

There’s nothing wrong with buying a hybrid to save on fuel costs, but maybe it’s time to put down the “I’m doing it for the environment” flag and put up the “I’m doing it to save money on gas” one. And there’s nothing wrong with that, of course.

If you’re interested in the details, check out the full 450-page report.