Biodiesel is a Greener Fuel
Diesel is a fossil fuel that, like gasoline, is created by refining petroleum. The exciting environmental twist on diesel fuel involves options for producing it from non-petroleum sources that burn cleaner because they don’t release the greenhouse gases that petroleum-based diesel does.
Diesel fuels can’t be used in gasoline engines, and vice versa.
Diesel fuel historically has had a high sulfur content, which not only is linked to health problems but also creates problems within vehicle emission systems. Old-style diesel deserves its reputation as a dirtier fuel. But new technologies are helping clean up diesel and the air. Modern innovations include:
Commercial biodiesel: Biodiesel refined from soybean and vegetable oils is processed and available commercially at fuel stations around the United States.Credit: Brand X PicturesThe higher the biodiesel content, the better for the environment.
Although technically you can use commercially refined biodiesel of any concentration in any diesel engine without converting it, the reality is that many major vehicle manufacturers won’t honor their engine warranties if you’re running biodiesel at concentrations above 20 percent biodiesel because of uncertainty about biodiesel’s effect on parts. Plus, biodiesel needs warming or additives in cold climates because it gels at warmer temperatures than regular diesel does.
One major concern with commercially produced biodiesel is with replacing food crops with biodiesel crops. But biodiesel can easily be made from agricultural waste, which makes it much more renewable and less threatening to world food supplies.
Ultra-low-sulfur diesel: As of 2006, federal law requires the use of ultra-low-sulfur diesel in new diesel vehicles, so if you buy a new diesel car, this is what you get. The ultra-low-sulfur diesel is refined to contain less than 10 percent of the sulfur of regular petroleum-based diesel.
Ultra-low-sulfur diesel fuel is already available at many service stations around the country. In fact, many now offer both regular and ultra-low-sulfur diesel.
Grease cars: One form of biodiesel is used in what’s referred to as grease cars, cars with diesel engines adapted so that they run on used vegetable cooking oil (often from restaurants). If your vehicle has a diesel engine, you can convert it to run on used cooking oil with an engine conversion kit. You can expect to get about the same amount of mileage from used cooking oil as from regular diesel — but without the greenhouse gas emissions.
Many grease car's owners go to restaurants to ask for the used oil and process it themselves (it’s not difficult), but services are cropping up around the country that do this processing for you.