The Porsche 911 released in the 1970s was equipped with the most complex fuel injection system ever designed called the Porsche 911 MFI or mechanical fuel injection system. As a mechanical system, the MFI requires regular maintenance to ensure it provides the correct amount of fuel and air to the engine. The MFI consists of two main components - the injection and distribution components and the throttle bodies. It works by using a fuel pump and compensating unit to supply the correct amount of fuel to each cylinder depending on engine speed and size. The MFI design was originally developed for diesel engines but was first used by Porsche in their 1969 Carrera and later 911 models.