As seen on:

SMH Logo News Logo

Call 1300 303 181

Australia’s Best New Car News, Reviews and Buying Advice

Clearing Up The Myths About Biodiesel

Biofuels are widely touted as being a solution to the dual problems of (1) limited fossil fuel supplies and (2) too many carbon emissions. In a nutshell, biodiesel is produced by taking crude oil from a source that isn’t a fossil fuel (i.e. not rock oil or petroleum oil) and doing all the chemical this and that to refine it so it can be used in our cars… or at least our diesel-fuelled cars.

However, there are a few rumours out there about biodiesel that are putting off a few people from giving it a go or adopting it.

Myth #1: Biodiesel will drive up food prices.

Facts: The thinking is like this: if we use, say, corn or sunflower oil to make biodiesel, this means that land that is currently used for growing food will be used to grow biodiesel feedstocks, which means there will be less food around, which means that food prices will go up. Even if crops aren’t competing for land, they may have to compete for fertiliser and water. This is a valid concern but we don’t have to choose between growing corn for our cornflakes and growing corn for oil. This is because biodiesel comes from a variety of sources. The good oil can be produced by algae that grow in septic tanks using grotty water that you’d never use on food crops. It can be harvested from the nuts of jatropha trees that grow on land that is no good for food crops. Waste oil and grease from fast food outlets (yep – all the oil from frying Kentucky Fried Chicken is good for making biodiesel) can be turned into biodiesel. They also use tallow sourced from animals – all the fatty bits that the butchers and slaughterhouse folk chop off a carcass because we don’t want to eat them can go for biodiesel as well as soap. I dare say that they could use the oils from the “fatbergs” found in sewers if they wanted to. It’s a case of being clever and using a range of sources to source the feedstocks for biodiesel, not just a few.

Just to throw a new twist into the food versus fuel debate, a lot of the corn grown in the US ends up as the ghastly corn syrup used to sweeten soft drinks and add to the obesity problem (corn syrup is also used to make the fake blood used in movies). Speaking for myself, perhaps it wouldn’t be a bad thing if we used less corn for making us fat and more for powering our cars!

Myth #2: Biofuel is still just an experimental fuel and hasn’t been tested properly.

Facts: There are whole scientific journals dedicated to biodiesel and biofuel research, covering everything from test cases looking at how well putting a fleet of buses onto biodiesel cuts emissions through to finding great new strains of algae that produce more biodiesel-suitable oil. So it’s certainly been tested and isn’t experimental. Of course research is ongoing – the same applies to methods of agriculture and medicine. Regarding whether it’s still a bit dodgy and uncertain whether you can put it in your vehicle, biodiesel had been tried out and it works just fine.

As a matter of fact, when Herr Diesel first invented the type of internal combustion engine that bears his name, he ran it on what we’d call biodiesel sourced from peanut oil. The engines had to be modified a little to take fossil fuel-sources diesel instead. So biodiesel is actually the older option and isn’t as new as you think.

Myth #3: You can only put biodiesel in a specially designed diesel engine.

Facts: While some car manufacturers – notably Mercedes-Benz about 10 years ago – trumpeted the fact that some of their models could run on biodiesel, the fact is that any diesel engine can run on biodiesel. However, it is true that because biodiesel is more of a solvent, it will loosen old deposits from the tank and pipes inside your engine, which means that you’ll have to check and change the filters more often at first if you make the switch to biodiesel. Apart from this initial clogging issue, any diesel engine can run on biodiesel. You can use biodiesel straight (known as B100) or a blend, depending on what’s available and what takes your fancy.

Cars that were made before 1993 can have problems with biodiesel, as the rubber pipes can’t handle this. If you like the idea of biodiesel and have an older model vehicle (and don’t want to take the opportunity to upgrade to a new car), then replacing the rubber hoses will do the job.

Obviously, you can’t run a petrol engine on biodiesel.  Owners of petrol-powered cars should look at ethanol and ethanol blends if they want a biofuel alternative to fossil fuels.

Myth # 4: Using biodiesel puts out just as much exhaust and pollution as regular diesel, so you’re not actually cutting down on emissions by using biodiesel.

Facts: For a start off, when it comes to cutting down on carbon dioxide emissions and other greenhouse gases, remember that producing the oils for biodiesel tend to come from plants and algae (and some animal fats in the case of waste oil from food outlets). While the algae or the corn plants or the jatropha trees are growing the oil-bearing seeds, they are quietly using the carbon dioxide in the atmosphere, so across the whole lifecycle of the biodiesel, this does mean fewer emissions and a smaller carbon footprint than fossil fuel-based biodiesel.

Secondly, a few tests run in the USA found that biodiesel exhaust doesn’t contain as many nasties so it burns cleaner. As far as I can make out, it’s kind of like the difference between wood smoke and coal smoke. Biodiesel exhaust doesn’t have as many sulphates, hydrocarbons or carbon monoxide, or as much particulate matter. This means that biodiesel reduces the amount of black smoke coming out of your diesel engine.

Some people claim that the exhaust fuel from cars running on biodiesel smells like hot chips and makes them feel hungry, especially if the biodiesel in question has been recycled from the stuff from fast food deep frying vats.


Myth #5: Biodiesel lowers your car’s performance.

Fact: OK, this one does have some basis in truth. If you put in 100% biodiesel into your engine, it won’t perform quite as well as if you used 100% petrodiesel or a petro-bio diesel blend. However, we’re only talking a 5–10% reduction in performance.  This means that you will notice a difference out on the race track or if you’re pushing your car to the limit – or possibly towing a very heavy load. However, for the average run about town picking up the groceries, dropping off the kids and going to work, you won’t really notice the difference.

My suggestion for a compromise here would be to use a petro-bio blend when towing but straight biodiesel for everyday driving.