Biodiesel is a processed fuel derived from biological sources that can be readily used in diesel-engined vehicles. It is produced by chemically treating waste or virgin pressed vegetable oils, such as oilseed rape or soybean oil. Although biodiesel is not necessarily a very clean burning fuel, it is made from a renewable source.

Bio-diesel can be used as a 5% blend with ultra-low sulphur diesel (ULSDF) in any diesel vehicle without affecting engine warranties. Although many modern diesel engines can run on pure biodiesel, few vehicles are actually warranted to use it as such, so check with your manufacturer before using. Since biodiesel acts as a solvent it can degrade rubber parts in vehicles built before 1990. However, modern rubber replacements are nor affected.

Biodiesel actually cleans the engine, and so fuel filters may become clogged with particulates if a quick transition to pure biodiesel is made from fossil diesel. It is therefore suggested biodiesel is gradually phased into the fuel supply of vehicles that have previously run on fossil diesel, and that the fuel filter is changed within 600-800 miles.

In severe winter conditions pure biodiesel may become waxy, making it difficult to start the engine; however, the use of additives or the addition of standard diesel to the blend can combat this problem.


  • Is produced from renewable energy sources
  • Is biodegradeble and non-toxic
  • Produces a net carbon dioxide emission into the atmosphere 78% lower than non biofuels
  • Produces less particulate emissions compared to conventional diesel engines
  • Is usually cheaper than standard diesel
  • Produces more nitrogen oxide NOx tailpipe-emissions than standard diesel
  • May start to gel at low temperatures
  • May degrade rubber parts in vehicles built before 1990