| Vol. 7 | No. 4 | Fall 2005 |
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Dialogue
Some people say diesel fuel is "dirty." Is biodiesel a better alternative? |
For conscientious consumers who already own a diesel vehicle, biodiesel offers an opportunity to reduce most of the tailpipe pollutants associated with conventional diesel—including the heat-trapping gases that contribute to global warming. However, biodiesel can produce more smog-forming nitrogen oxides than conventional diesel.
Biodiesel is derived from vegetable oils or animal fats. Some vehicle owners modify their diesel engines so they can pour used cooking oil (from a restaurant’s deep fryer, for example) straight into their fuel tanks, but the simplest option for most drivers is to purchase biodiesel that has already been refined for use in conventional diesel engines with little or no modification. Prospective customers should keep in mind that biodiesel is often blended with standard petroleum-based diesel to lower the cost and prevent possible operational issues in cold weather, but as the percentage of biodiesel in the blend decreases, so do the environmental benefits.
When the time comes to buy a new car, stick with gasoline-powered models for now, which produce less toxic soot and smog-forming emissions than diesel vehicles (including those fueled with biodiesel). If you really want a diesel vehicle, consider waiting a couple of years until the diesel vehicle fleet meets tougher emission standards. And if you already own a diesel vehicle, fueling with biodiesel can reduce your environmental impact today.
To learn more about biodiesel, visit the Clean Vehicles section of the UCS website at ucsusa.wsm.ga3.org/clean_vehicles.
Also in this issue of Earthwise:
Close to Home
An Edible Legacy
