Biodiesel Compatible?

My knowledge to date

The thing with Biodiesel is that in theory it can go into all diesel engines, as the diesel engine itself was designed to run on plant oil,  However it is the parts attached to the diesel engine which could potentially cause problems – although the vast majority of diesels on the road are fine running on 100% Biodiesel.

 All diesels on the road are fine on  Biodiesel blends up to 20% blend, and the majority of outlets in the UK are only a 5% blend; so filling up from most places is of course fine.  A blend of 5% is hardly worth it in a way, except that you support the industry and in doing so the availability and blends should increase over time, so I support buying it on that basis as it is a step towards more 100% Biodiesel outlets (as they have abroad).

Back to the point about compatibility.  Basically the vast majority of vehicles on the road are fine on 100%, but only a handful of companies have done the research and minor adjustments to officially approve 100% Biodiesel use in their new cars.  This is because – until the consumer starts to demand it more ( i.e. until it affects their sales) they can’t be bothered to do the research / minor changes; so I urge everyone to be a conscious consumer and buy cars from the companies that do honour their warranties on their vehicles when they use 100% Biodiesel.  I myself have used 100% Biodiesel in my private and work vehicles for over 5 years and none of the vehicles have the official approval from the manufacturers. The only problem I once had – now resolved – was a cold start problem. To avoid cold starts in winter use RME biodiesel only as this does not freeze until below minus 12C. Other kinds of Biodiesel made from waste cooking oil can freeze in winter. Don’t forget that a one-off fuel filter change is needed after you first make the switch to biodiesel.

 So, where does that leave us?

  1. The next vehicle you buy – buy from a company that  honours their warranty on 100% Biodiesel use – if you haven’t already done so, see for cars OK on Biodiesel officially.
  2. If you have a vehicle built before 1990, it is unadvisable to use 100% Biodiesel because natural rubber pipes were used up until about 1988 and these get eroded by Biodiesel (pipes, however can be fairly easily replaced if you want)
  3. I have no personal experience of using 100% on modern vehicles with high pressure diesel pumps so would be cautious on using 100% Biodiesel in those (i.e. for vehicles built after 2004, check if it has a high pressure pump).  What little experience there is on high pressure pumps, says up to 70% blends are OK

In short: any diesel built between 1990 and 2004 is fine!

 Final points:

A. Use Biodiesel of specification EN14214 only unless you are confident to use any other non-certified fuel.

 B. In winter Biodiesel made from recycled oils tend to gel up at about –3°C, so use only 50% blends in winter (for every 3% of fossil diesel added the freezing point of the Biodiesel drops 1°C). Alternatively, use RME biodiesel which doesn’t freeze in English winters.

Do what you can…otherwise the Earth’s had it! …. Adrian Lawton