June 2006
Biodiesel: A promising blend
Another renewable fuel that is getting a lot of attention is biodiesel, a fuel made from vegetable oil that can be used to
power diesel engines. Biodiesel is renewable, nontoxic, nonexplosive, and biodegradable, and it burns more cleanly than petroleum
diesel.
Biodiesel is fuel made commercially from vegetable oil treated with lye to make it more viscous, and with other substances to make it last longer in storage. Mostly it is used in blends with petroleum diesel, in mixes such as B5 (5 percent biodiesel to 95 percent petroleum diesel), B10 (10 percent biodiesel), and B20.
Currently, 100 percent biodiesel, called B100, costs about $3 a gallon compared with about $2.60 a gallon for regular diesel.
A gallon of B20 can operate most diesel engines with no modification. It costs about 15 to 25 cents more than a gallon of petroleum diesel, but it uses 20 percent less petroleum and burns cleaner.
Most biodiesel outlets are located in the Midwest. To see where to buy biodiesel, visit the Web site of the National Biodiesel Board.
Most makers of diesel cars will not honor warranties on cars that burn biodiesel in higher concentrations than B5 because it can eat away at seals in the fuel system.
According to statistics published by the U.S. Department of Energy's National Renewable Energy Laboratory, the U.S. will soon have the capacity to produce about 900 million gallons a year, or enough to supplant less than 1 percent of the gasoline used in this country.
In Consumer Reports' own tests, a car running on biodiesel produced slightly less pollution than the same car running on conventional diesel but achieved slightly fewer mpg.
A variation on biodiesel is straight vegetable oil (SVO), which can also burn in diesel engines without modification. Cars running on SVO, however, need a separate fuel tank for the veggie oil and a preheating system to keep it from congealing. Conversion kits to add the fuel tank and other hardware to existing diesels cost about $800, and the components reduce a vehicle's cargo space.
In our tests, the car running on vegetable oil posted almost the same acceleration and similar emissions as it did on petroleum diesel. Many people who go this route get free recycled fryer oil from restaurant kitchens. But it has to be filtered thoroughly before being put in the tank.
Biodiesel is fuel made commercially from vegetable oil treated with lye to make it more viscous, and with other substances to make it last longer in storage. Mostly it is used in blends with petroleum diesel, in mixes such as B5 (5 percent biodiesel to 95 percent petroleum diesel), B10 (10 percent biodiesel), and B20.
Currently, 100 percent biodiesel, called B100, costs about $3 a gallon compared with about $2.60 a gallon for regular diesel.
A gallon of B20 can operate most diesel engines with no modification. It costs about 15 to 25 cents more than a gallon of petroleum diesel, but it uses 20 percent less petroleum and burns cleaner.
Most biodiesel outlets are located in the Midwest. To see where to buy biodiesel, visit the Web site of the National Biodiesel Board.
Most makers of diesel cars will not honor warranties on cars that burn biodiesel in higher concentrations than B5 because it can eat away at seals in the fuel system.
According to statistics published by the U.S. Department of Energy's National Renewable Energy Laboratory, the U.S. will soon have the capacity to produce about 900 million gallons a year, or enough to supplant less than 1 percent of the gasoline used in this country.
In Consumer Reports' own tests, a car running on biodiesel produced slightly less pollution than the same car running on conventional diesel but achieved slightly fewer mpg.
A variation on biodiesel is straight vegetable oil (SVO), which can also burn in diesel engines without modification. Cars running on SVO, however, need a separate fuel tank for the veggie oil and a preheating system to keep it from congealing. Conversion kits to add the fuel tank and other hardware to existing diesels cost about $800, and the components reduce a vehicle's cargo space.
In our tests, the car running on vegetable oil posted almost the same acceleration and similar emissions as it did on petroleum diesel. Many people who go this route get free recycled fryer oil from restaurant kitchens. But it has to be filtered thoroughly before being put in the tank.
