 While sharing many design features such as staggered valve arrangement and rockers running off a single overhead camshaft driven by a duplex cam-chain, the engines were of completely different design with little or no inter-changeability of parts.The original M180 engine was rated at .It powered the W187 220 sedan, coupé, and cabriolet (Type A and B) from 1951 to 1955, the W180 220a sedan, coupé, and cabriolet from 1954 to 1956 and the W105 219 4-door sedan from 1956 to 1959.