Can you run your car on vegetable oil?

As the price of a litre of diesel this week topped £1.75, video surfaced of a driver in a supermarket car park filling his car's fuel tank with bottle after bottle of vegetable oil - footage which quickly went viral on social media. Vegetable oil from the supermarket costs as little as £1.15 per litre, and you can use up to 2,500 litres of it a year to fuel your car duty-free, but is it a wise thing to do?

Biofuels – fuels derived from plant or animal matter – are not a new idea. The Ford Model T, first produced in 1908, was originally designed to use ethanol, while Rudolf Diesel’s demonstration engine of 1912 ran on peanut oil. However, it wasn't long before these biofuels were replaced by petroleum-based fuels, which could be mass-produced more cheaply.

Will my car run on cooking oil?

Some older diesel engines will run on cooking oil and even used oil that has been strained. However, the viscosity of cold oil can cause fuel injectors to clog. Modern diesel engines on the other hand require it to be enhanced and there are companies that specialise in turning used cooking oil into biofuel.

Can I make my own biofuel?

There are ‘recipes’ available on the internet for the domestic production of biodiesel. These usually involve mixing methanol with sodium hydroxide and pouring the resulting mixture into vegetable oil. Such home production raises serious health and safety concerns, as it involves hazardous chemicals and the risk of fire and explosion.

Making biodiesel is a potentially hazardous process that should only be carried out in controlled conditions by people with the proper training and experience. Quite apart from these risks, a poorly made biodiesel could seriously damage a vehicle engine.

How green is biofuel?

The production and use of biodiesel produces less carbon dioxide than fossil fuels. Well, that’s the theory, and it's the reason the stuff sold at your local petrol station contains around 1o per cent of it. However, calculating how much carbon dioxide's produced by burning the fuel in your car is a complex process that's dependent on exactly how the biodiesel is produced and, just as importantly, wider impacts such as change in land use.

Figures used by the British government, which acknowledge the environmental cost of the production and transport of biodiesel, overlook the effect of land use change associated with biofuel production.

The use of biodiesel for transport was intended to reduce CO₂ emissions, but analysis of the European Commission’s latest study on biofuels has found it is set to increase Europe’s overall transport emissions. The analysis takes into account the 7% cap on the contribution of biofuels produced from food crops.

The EU study found that palm, rapeseed and soy-based biodiesel has land-use change emissions that alone exceed the full life-cycle emissions of fossil diesel. The analysis by T&E adds to these figures the direct emissions of biofuels from tractors and fertilisers etc.

Biodiesel from virgin vegetable oil leads to around 80% higher emissions than the fossil diesel it replaces. Soy and palm-based biodiesel are two and three times worse respectively. These biodiesels are the most popular biofuel in the European market.

The ethical choice

The ETA was established in 1990 as an ethical provider of green, reliable travel services. Over 30 years on, we continue to offer cycle insurance , breakdown cover and mobility scooter insurance while putting concern for the environment at the heart of all we do.

The Good Shopping Guide judges us to be the UK's most ethical provider.

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