3D animation the new MAHLE BlueDrain system. Modern injection systems for diesel engines require more and more effective wear protection. In addition to highly efficient particle and water separation in the fuel filter, automatic disposal of the separated water is increasingly important. That is why MAHLE has developed the BlueDrain system for diesel fuel with a high water content, which will be available in the future as both a stand-alone system and an integrated system unit in MAHLE fuel filter modules.