In Translogic episode 6.3 we explore biodiesel, the alternative to petroleum-based diesel fuel. Yes, there are big benefits, but the question remains: Will it work for the average diesel passenger car?

Biodiesel may seem like some sort of strange alternative fuel used only by that guy, you know, the one who's always talking about his Burning Man plans. But according to the independent research organization World Watch Institute, global bio-fuel production topped 81 billion liters (including 15 billion liters of biodiesel) in 2008. Despite the big numbers and impressive claims of many biodiesel advocates, most people are still a little confused about it and many more have simply never heard of it.

Here are a few things you should know before you decide to pump biodiesel into your car.
What is biodiesel?

Biodiesel is an alternative fuel that's made from renewable resources like used vegetable oil, animal fat and other forms of waste. It can also be made from plants such as soybeans. General Motors and the Department of Energy are even working to develop biodiesel from the jatropha plant which is generally considered a weed. After processing and cleaning the raw source material, one of the resulting chemicals is methyl esters, which are flammable and can be used as a fuel. The other resulting chemical is glycerin, which is used in soap and cosmetics.

What's so great about biodiesel? Are there any drawbacks?

Several factors make biodiesel appealing, mainly that it's made from domestic renewable resources. Also, biodiesel burns cleaner, has a more moderate odor and is biodegradable. According to the National Biodiesel Board, use of biodiesel reduces lifecycle carbon emissions by 60-80 percent. Clearly, there are advantages to biodiesel, but it isn't perfect. In order for biodiesel to really be viable, it is usually blended with regular, petroleum-based diesel fuel. Also, in the U.S. biodiesel is more expensive than traditional diesel fuel; biodiesel can cost as much as 70 cents per gallon more than petroleum-based diesel. Biodiesel is no magic bullet but it's does provide a way to partially power cars and truck with a renewable, domestically produced fuel that's less harmful to the environment.

What is B5, B10 and B20 biodiesel?

These fuels are known as biodiesel blends, a combination of biodiesel and petroleum-based diesel fuel. The number behind the "B" is the percentage of biodiesel in the blend -- B5 is 5 percent biodiesel and 95 percent regular diesel fuel, B10 is 10 percent biodiesel and 90 percent regular diesel fuel and so on.

Can I use biodiesel in my car?

Yes and no. The US Department of Energy and Department of Transportation both consider biodiesel an acceptable alternative fuel. It's also been approved by the Environmental Protection Agency as a fuel and fuel additive. Still, using pure biodiesel in modern passenger cars has serious limitations. In colder climates, pure biodiesel may thicken and not work properly and can clog various fuel filters. Using pure biodiesel may void your car's warranty since automakers do not recommend it. That's why most biodiesel being pumped by consumers today is a blend.

Vehicles like the Mercedes Benz GL350 bluetec, Audi A3 and Q7 TDI, VW Jetta and Golf TDI can run on B5 biodiesel blend without jeopardizing the warranty. Older diesel vehicles can run even higher levels of biodiesel safely. Recently, GM announced that it will offer the option of a 6.6-liter Duramax turbo-diesel engine that's approved to run on a biodiesel blend up to B20. The B20-compatible engine will be offered in the 2011 Silverado and Sierra HD pickups as well as the Chevrolet Express and GMC Savanna full-size vans. The best thing to do is check with your vehicle's manufacturer before pumping biodiesel into the fuel tank.

Can't I just recycle used cooking oil instead?

No. Biodiesel has been processed to make it an approved and safe energy source. Cooking or vegetable oil is a not an approved fuel and will produce more pollution than biodiesel.

Where can I get biodiesel?

Biodiesel.org has several lists and tables that can help find a biodiesel retailer in your state, by zip code, or along a desired travel route.

Click the image below to watch episode 6.4