Alternative Fuels Glossary

Ford, among others, is "still working on" a clean diesel, said Paul Kilgore, director of environmental science. Engineers "pretty much know how to deal with particulates," but NOx (nitrous oxides) reduction remains an obstacle.


Kilgore notes two methods to reduce NOx emissions: 1) Precious metal technology, "still in the research stage" and 2) a less-costly method that requires the customer to add an additive every 5,000 to 10,000 miles.

Biodiesel
Domestically produced and renewable, biodiesel can be made from vegetable oils, animal fats, or recycled restaurant greases. Safe and biodegradable, biodiesel reduces such pollutants as particulates, carbon monoxide, hydocarbons, and air toxics.


Some observers have noted that biodiesel vehicles emit an aroma reminiscent of french-fry grease, but that depends on the original source. Biodiesel-powered vehicles "can run seamlessly," Cogan said. "I think biodiesel will be a big thing."

Natural Gas (CNG)
Primarily used in fleets, natural gas is one of the cleanest-burning fuels. It's available through the utility infrastructure.