Today's bacon fat could be tomorrow's biodiesel.
Today's diesel engines can run on a processed form of grease. Common restaurant grease and cooking oils, when processed into biodiesel, provide an alternative to dependence on fossil fuels.
Biodiesel
Before grease or vegetable oil can run a car's engine, it must undergo processing into its refined form, biodiesel. The Chicago Tribune noted that in 2007 the United States produced 450 million gallons of this newly popular alternative fuel.
Sources
Used cooking oil and restaurant grease provide plenty of raw material for biodiesel. A Chicago Tribune article states that some restaurants get paid to ship off their used oil and grease for processing. San Francisco has launched a citywide grease recycling program, according to SFGate.com.
Grades
The U.S. Department of Energy lists several grades of biodiesel-petroleum diesel blends, noting that the B2 and B5 grades can power most diesel engines.
Pros and Cons
While biodiesel emits less pollution and uses largely recycled, renewable materials, it currently costs more and delivers less power and lower fuel economy than standard fuels, according to the U.S. Department of Energy.
Considerations
The U.S. Department of Energy warns that trying to use unprocessed vegetable oil or grease will harm a vehicle's engine and advises drivers to use fully processed biodiesel only.