Someone recently presented me with this interesting scenario: "If I buy an SUV but run it on biodiesel, is it still bad for the environment?"

The short answer is no – this set-up is a lot cleaner than a small gasoline car for a couple of reasons. First, biodiesel comes from plants that were recently grown, which means that the CO2 released from burning it was recently removed from the air – in other words, you are not adding any greenhouse gases. And second, biodiesel burns much cleaner than gasoline or diesel, which leaves you with far fewer overall pollutants. You should still consider fuel economy though. For example, a Mercedes SUV uses about the same amount of fuel as a gasoline powered VW New Beetle (Diesel VWs do much better), but this is not the case for all diesel vehicles, so check that window sticker so you don’t get stuck with a fuel guzzler!

Biodiesel is a great option, but for the long term it’s not an ideal solution. The worry is that producing biodiesel in commercial quantities to replace our current gasoline consumption would use up far too much farm land, which could threaten our global food supply, or at least link our food prices to our fuel prices, which nobody would enjoy (except maybe the farmers!). So even when using biofuels we will still need to drive more fuel-efficient cars, drive them less, and drive them more efficiently.

What’s great about biodiesel right now is that with a little bit of effort you can cut your fuel costs significantly. Diesel powered vehicles are generally much more fuel efficient than comparable gasoline powered vehicles, so you’re already saving a fair bit, but you can save even more money by making your own biodiesel. It’s a simple process that uses some basic chemicals to turn waste vegetable oil and grease into a clear, thin fuel that is actually better for your car than regular diesel is. There are plenty of free resources online that will show you how to do this. Working with grease can get a bit messy, of course, but that’s part of the fun! The best part is that this process starts with a waste product – the oil used is not being taken out of anyone’s food supply. There’s a certain satisfaction that comes from taking something most people see as waste (restaurants pay good money to have the oil/grease taken away) and turning it into something valuable.

I should take this opportunity to quickly explain the difference between biodiesel and waste vegetable oil (WVO), because many people think they are the same. Briefly stated, biodiesel is refined waste vegetable oil. To make biodiesel you take the waste oil, add some chemicals, and process it. The resulting fuel is a direct replacement for regular diesel fuel – your vehicle does not need any modifications – and your engine actually runs better on it!

Waste vegetable oil is just that – unrefined waste oil straight from the deep fryer. Just run it through a filter and put in your tank. To safely run your car on WVO, it needs to have a conversion kit to preheat the oil and to flush the thick oil out of the fuel lines when shutting down.

Both methods have their pros and cons: Biodiesel processing costs money and takes time; WVO requires an expensive conversion and you have to start and stop your engine the right way every time you use it.

So there you have it – biodiesel in a nutshell!