Mercedes-Benz built the first production car to use a turbocharged diesel engine, the Mercedes-Benz 300SD.
The 300SD was part of the W116 Mercedes-Benz S-Class range and was introduced in 1978 for the North American market. Its five-cylinder diesel engine used a turbocharger to improve performance while retaining the fuel-efficiency advantages associated with diesel power.
The model was developed partly in response to United States fuel-economy pressures and became an important technical milestone for passenger cars. Turbocharging had already been used in other kinds of vehicles and racing applications, so the claim concerns a production passenger car rather than the first turbocharged engine of any kind. Mercedes-Benz later expanded diesel technology across additional models and markets.