380 SE, SEL W126 09/1983 - 08/1985 M116.961,963. 450 SEL W116 08/1975 - 08/1980 M117.986. 450 SEL 6.9 W116 09/1976 - 08/1979 M100.985. 500 SE, SEL W126 12/1979 - 08/1985 M117.961,963. This is probably because of modern fuel additives & the introduction of ethanol into fuel.
