The W123 chassis of the Mercedes-Benz 300D was introduced as a 1976 model (1977 U.S.). Its 3.0 litre five-cylinder diesel engine with indirect injection (using a Bosch MW for the American market, or W for the rest of the world) piston-type mechanical fuel injection pump, produced 80 to 88 hp (59 to 65 kW), depending on the year or country. This model features an extra 600 cm³ displacement compared to the four-cylinder Mercedes-Benz 240D diesel. The W123 chassis evolution continued with the addition of the 300D Turbo Diesel in 1982 (1981 for station wagon), sporting a 3.0 litre five-cylinder Garrett turbocharged engine which was originally developed in 1978 and first offered in the US market for 300SD models in 1979. This engine developed 118 to 123 hp (88 to 91 kW) and considerably improved the car's performance while still maintaining the superb reliability and efficiency of earlier models. In addition to the sedan (300D) a station wagon (300TD) and coupe (300CD) were also produced. The 300TD also had optional rearward facing third row seat which could fold flat into the floor, which was also seen on Volvo, Saab 95 and Ford Taurus station wagons.
The W124 chassis 300D (pre E Class facelift) has the OM603 engine, which is a 3.0 litre six-cylinder turbocharged engine that appeared for one year only, 1987. The Turbo Diesel W124 appeared anew in 1990 until 1993, as the 300D 2.5 Turbo, with the OM602 engine. The latter engine was a 2.5 litre five cylinder turbocharged engine.