 In 1959 the first series of W111 "Fintail" 220SE and 220SEb models was introduced, with the carburetted M180 in the 220b and 220Sb and the M127 used in the 220SEb.The addition of the lower case ‘b’ was added to differentiate the Fintails from the earlier Pontons.In 1965 the W111/W112 sedans were superseded by the new W108/109 series 250 and 250S (apart from the W111 230/230S, produced from 1965 to 1968).