Mercedes-Benz model nomenclature in the 1960s is difficult to follow once the tailfins disappear. The W108 and W109 family of sedans can mostly be recognized by the grille and front fenders from the 1961 W111 design, with cathedral headlights in the European versions, which were replaced by vertically stacked 5-inch lights in the U.S.
Mercedes-Benz's 250 series replaced the 220 and 230 six-cylinder models, and served as the company's sensible sedan, with subdued design, leatherette interior, durable construction, and decent performance.
The rear fins went away in 1965, and the new body was longer and lower. A new 2.5-liter 7-main bearing, 128-hp, six-cylinder engine appeared in the 250S and 250SE sedans and was replaced in 1968 by the 2.8-liter variation which generated 180 hp. The 280S, 280SE and 280SEL – "L" is the long-wheelbase version – all have Bosch fuel injection and gained four-wheel disc brakes. The hood and grille were lower by a couple of inches for 1969giving the car a more modern appearance.
A series of handsome W111 280SE coupes and convertibles were made in parallel, with the same engine advances and a 3.5-liter V-8 were available from 1969 to 1971. Well maintained SE convertibles are prized possessions today and command strong prices. The ultimate version of this series is the 6.3-liter 300SEL, which offered the 250-hp, hand-built V-8 from the 600 and 600 Pullman. Capable of eclipsing 140 mph they are one the most sophisticated cars of the era, and can be correspondingly complex to keep in good running order.