Background The Mercedes-Benz W123, produced between November 1975 and January 1986, represents one of the most successful chapters in the brand’s history.

Positioned as an executive-class vehicle, the W123 range succeeded the W114 and quickly eclipsed it in popularity.

By the time production concluded—autumn 1985 for saloons and January 1986 for coupés and estates—Mercedes-Benz had sold an impressive 2.7 million units, cementing the W123's status as the company’s best-selling model of its era.

The OM616 is a diesel inline-four engine developed by Mercedes-Benz and widely used throughout the 1970s and 1980s.

While its production in Germany has long since ended, the engine continues to be manufactured by Force Motors in India, where it has remained in use from the 1980s to the present day.

Originally designed as an enlarged successor to the 2.2-litre OM615, the OM616 powered a broad range of vehicles over its lifetime—including passenger cars, vans, and the rugged Unimog utility ve...