Mercedes-Benz M118 engine

The Mercedes-Benz M118 is a four-stroke inline-four engine produced from 1965 to 1972. It was originally developed by Mercedes-Benz for the mass-produced vehicle segment, but it was first used by Audi in the F103, after Daimler sold the company to Volkswagen. The engine replaced the earlier two-stroke engines, used a Solex carburettor and had swirl-inducing intake ducts that allowed smoother running and better efficiency. It was revised several times with larger displacements and lower compression ratios for reliability, and its success let Audi move into more upscale market segments. Volkswagen engineers later used its overhead valve four-cylinder layout as the basis of the 2.0 litre single overhead camshaft EA831, which went into the Audi 100, the Volkswagen LT and eventually the Porsche 924.