Biodiesel blends are excellent substitutes for conventional petroleum diesel with an array of environmental advantages as well as better usage features. Engine modifications may only be required when pure biodiesel (B100) is used so as to avoid maintenance and performance problems. For blends such adjustments are not necessary and thus switching from petroleum diesel to biodiesel is possible at any time. In order to ensure a smooth conversion without complications we recommend the following, while for more detailed information you may also contact your vehicle manufacturer.

Petroleum diesel typically forms deposits in vehicles’ tanks or fuel pipes. Because biodiesel is an oxygenated fuel it will loosen these sediments and carry them into the fuel systems, where they can clog fuel lines and filters. Therefore we recommend the fuel filter to be replaced, once the tank has been filled a few times. The problem will then typically disappear, so that only the common service intervals need to be maintained.

Older engine models may use gasket and seal materials, which are not sufficiently resistant to the solvent property of biodiesel, especially those made from natural or nitride rubber. When exposed to spillage, these swell over time and leak. Fuel pumps may contain rubber valves that may fail. Therefore we recommend regular inspections and replacement of non-solvent-resistant materials.

Though most manufacturers nowadays use solvent-resistant dual component lacquers, some older coatings will slowly macerate and peel away after having been exposed to biodiesel. For this reason we recommend to wipe clean any surfaces, which may have been in contact with biodiesel spillage during tank filling.

In exceptional cases, depending on the engine model of the used vehicle, motor oil can become diluted with non-combusted fuel. Increases in the oil level indicate such dilution, which in turn calls for a regular check and if necessary also for an oil change.

During the storage of petroleum diesel, deposits of cold sludge typically build up in the respective tank. Therefore it is imperative that the storage tank be thoroughly cleaned before a switch to biodiesel (removing water and accumulated sediments). Insufficient cleaning before using biodiesel blends of 30% or higher can result in excessive fuel filter plugging and thus lead to fuel injector failures. In addition, the storage tanks should not be lacquered on the inside as the lacquer will dissolve. Because of the hygroscopic properties of biodiesel, special efforts must also be made to prevent water from entering the tank and mixing with the fuel.