Mann Filters for Porsche® In 1941, Adolf Mann and Dr. Erich Hummel founded Filterwerk Mann + Hummel in Ludwigsburg, Germany. The company began producing engine air and oil filters after acquiring filter-production work from MAHLE, and from there they grew into one of the world’s leading filtration specialists. MANN is best known today for manufacturing oil filters, air filters, fuel filters, and crankcase ventilation filters designed to meet original-equipment specifications.