Everything You Need To Know About Biodiesel

Biodiesel can be produced from straight vegetable oil, waste cooking oil and even animal fats, which when converted can be used as an alternative fuel. This is not only great for the environment but also saves you plenty of money in the long run.

Tweet Pin It
4Car is reader-supported. When you buy through links on our site, we may earn an affiliate commission. Find out more.

Rather than using petrol or diesel, biodiesel is an alternative fuel that can be used in a number of older diesel cars. The majority of people decide to use biodiesel as a means of saving substantial costs. However, many others may simple use it as a more environmentally friendly fuel because it produce no carbon dioxide.

In terms of the production of biodiesel, it can be produced from vegetable oil, animal fats, tallow and waste cooking oil. In order to convert these liquids into biodiesel, it needs to go through a process called transesterification. It sounds like a complex conversion but it’s relatively straightforward and basically involves mixing reactants.

By far one of the cheapest and most popular methods of creating biodiesel is by using waste vegetable oil. This can be sourced from chip shops, commercial food manufacturers and various restaurants. It’s a win-win for both parties because by using waste vegetable oil, you are helping out the business by getting rid of the waste but using it your advantage. Of course, the waste vegetable oil will need to be treated but the cost savings make it a worthwhile task.

Benefits of Biodiesel

One of the main reasons for drivers to switch to using biodiesel is primarily to save money. Considering that you can get waste vegetable oil for free, it’s a no brainer. As long as you are willing to spend some time converting the oil into biodiesel, it could potentially save you a fortune in the long run.

The environmental properties is another great advantage because biodiesel’s are carbon neutral. This is due to the fact that the minimal carbon dioxide produced is equal to the carbon dioxide that is absorbed by the plants.

Another benefit is that it’s rapidly biodegradable as well as being non-toxic. This means that spillages are less of a risk and in the event of a crash, it has higher flash point than a conventional fuel.

Other potential advantages of biodiesel’s include:

  • Extends the lifespan of catalytic converters due to the lack of sulfur
  • Doesn’t require alterations to diesel engines
  • Can lengthen the lifetime of the engine due to the additional lubricity
  • Renewable energy source

As you can see, there is multiple reasons to switch to an alternative fuel such as a biodiesel. Of course, there are some drawbacks but some of the benefits far outweigh them for many people.

What Cars Are Compatible With Biodiesel?

Pouring biodiesel straight into your brand new car isn’t advised and can cause expensive damage to the engine. Modern engines are far more complex and use multiple ECU’s to control the flow of fuel to certain components of the engine.

For example, one component that would be prone to fail within a modern engine would be the high pressure common rail and injectors. Another component that could fail would be the fuel pumps because the vegetable oil will have a far higher viscosity (liquid thickness) compared to a convention oil.

Older cars that use indirect injection are the best vehicles to use (or convert) as they are far less complex. Some of the diesel cars that we recommend to use biodiesel fuel in include:

  • Mercedes – W123, W124, w210 (E300 TD not the CDi’s), W126 and older
  • Volvo – 240, 740, 940
  • Peugeot – 306 (1.9 XUD engines are great)
  • Volkswagen – Golf, Jetta, Polo, Passat (most pre-2000)

If you are already thinking about using biodiesel, you will more than likely own a car that is compatible. The recommendations above are the most common biodiesel compatible cars in the UK.

Are There Any Disadvantages?

As great as biodiesel fuels are, they do have disadvantages that put many people off using it on a daily basis. The biggest disadvantage is the inconvenience of getting the fuel when compared to diesel or petrol. You not only need to source the straight or used vegetable oil but you may also need to convert it too.

Other disadvantages of using biodiesel include:

  • Harder to start in the cold
  • Odd smells when handling it and when burned
  • May void warranties (although not relevant for older cars)
  • Expensive to convert modern vehicles
  • Can damage fuel pumps and injectors
  • Requires more maintenance

With the help of some additional maintenance products, you are able to avoid certain complications. For example, if you invest into some highly rated diesel injector cleaners, you are able to keep them in good condition.

You can also use a diesel additive and mix it into the fuel in order to maximize its performance. Whenever using biodiesel, you should expect to perform additional maintenance but this shouldn’t be too much of an issue.


In order to reap the benefits of using a biodiesel for fuelling your car, you will need to be make some sacrifices. However, the same can be said when using an electric car as an alternative. For example, you will need to not only purchase a home EV charger but also remember to charge the car.

To conclude, if you are more than willing to be hands on with the handling of vegetable oils, biodiesel is worth trying out. However, do you homework beforehand to ensure that your car is compatible with biodiesel.

author dan 4car

Written By Dan

Dan has been a car enthusiast ever since he can remember and has an extensive range of cars that include classic cars that he has restored himself from a barn find condition to modern performance cars. Whether you need advice on how to install car parts or recommendations on what products to buy, Dan’s first-hand experience will certainly help.

If you want to find out more about Dan, our testing process or the website itself, visit our about page for further information.

Follow #4CarUK

Copyright © 2021. All rights reserved.