Mercedes-Benz M18 engineThe Mercedes-Benz M18 engine is a naturally-aspirated, 2.9-liter, straight-6, internal combustion piston engine, designed, developed and produced by Mercedes-Benz; between 1933 and 1937.M18 EngineThe six-cylinder 2,867 cc side-valve engine produced a maximum output of at 3,200 rpm. In 1935 the compression ratio was increased along with maximum power which was now given as. Power was delivered to the rear wheels via a four-speed manual transmission with synchromesh on the top two ratios.ApplicationsMercedes-Benz W18