Fuhrmann was responsible for the so-called Fuhrmann-engine, used in the 356 Carrera models as well as the 550 Spyder, having four overhead camshafts instead of a central camshaft with pushrods, as in the Volkswagen-derived serial engines.
Fuhrmann foi o responsable do chamado motor Fuhrmann, utilizado nos modelos 356 Carreira, así como no 550 Spyder, que ten catro árbores de levas en lugar dunha árbore de levas central con varillas de empuxe, como nos motores de serie derivados de Volkswagen.