The use of biofuels helps conserve finite fossil resources and minimise CO₂ emissions. However, despite its many advantages, running on biofuels can have a negative effect on engine lubricating oil. For example, biodiesel and vegetable oil accumulate in the engine oil due to their high boiling point and significantly accelerate the ageing of the lubricating oil. High biofuel content in the oil and high thermal loads can cause the lubricating oil to thicken suddenly, which is equivalent to a total failure of the lubrication system. For safety reasons, the lubricating oil change intervals in biodiesel and vegetable oil operation have therefore been halved, which is a high cost factor and has a negative impact on the environment.

The aim of the project is to develop a fast and cost-effective ageing test for lubricating oils in biodiesel blends in order to be able to select the optimum lubricant for this application in advance and avoid critical oil conditions.

Furthermore, in-depth mechanistic investigations into oil thickening are being carried out in order to develop suitable countermeasures. The influences of various additives on the ageing resistance of different engine lubricating oils are also being investigated.