Driving smarter (which we take to mean driving less and polluting less when we do drive) is about more that what your CO2 emissions are and your MPG rating, it's about feeling greener, better. There is a lot of attention (here and everywhere else, it seems) on ethanol
as a way to drive cleaner, and in a lot of ways ethanol is better (greener) than regular old gasoline. But the big variable is how the ethanol is produced. Recently, Grist
took a look at how some of the mega-ethanol producers use coal, a fuel that has never had a lot of green connotations. The U.S. EPA
is "considering a rule change under the Clean Air Act that would relax pollution regulations on ethanol plants, clearing the way for them to burn coal with fewer restraints," writes Amanda Griscom Little in Grist. The number of coal-powered ethanol plants is expected to increase dramatically in the next few years, so drivers will have to make even more calculations
when deciding whether or not their rides are green. Little's entire article is worth reading.