1984 Mercedes-Benz 300 Series

The new mid-size W123-series from Mercedes-Benz was introduced in 1975 for 1976 as a replacement for the outgoing W114 and W115 models. Through many individual models that were relentlessly developed and improved, production would continue through 1985. The highly versatile W123 would be offered in coupe, sedan, and station wagon body styles, along with short- and long-wheelbase chassis forms intended for specialized bodywork including ambulances, commercial, and police vehicles. The range of engines included gasoline, Diesel, and Turbodiesel which allowed it to accommodate a variety of buyer needs.

Along with coachbuilt examples, Mercedes-Benz produced its own factory-built limousines on the Long-Wheelbase (nearly 135 inches) W123 chassis, in both gasoline-powered 250 (V 123 V 25) and five-cylinder diesel-powered 300D (V 123 D 30) versions from September 1977 through late-1985.

In the United States, the 1984 Mercedes-Benz 300 Series included the 300D four-door sedan, 300CD two-door coupe, 300SD four-door sedan, and 300TD four-door station wagon. The 300D premiered at the 1975 Geneva Salon, with the estate-bodied 300TD version following two years later at the Frankfurt Auto Show. In company nomenclature, the 'C' represented 'Coupe,' 'T' for Tourismus (estate wagon), 'D' for 'Diesel' and 'E' for 'Einspritzung' (fuel injection). The long-wheelbase models were often designated 'Lang' or V123 in brochures and order forms (F123 for bare long-wheelbase chassis).

The inline, overhead-cam five-cylinder turbocharged engine diesel displaced 2,998cc (183 cubic inches) and had solid valve lifters, fuel injection, six main bearings, 21.5:1 compression, and delivered 155 horsepower at 4,750 RPM, and nearly 200 ft-lbs of torque at 2,750 RPM. Mercedes-Benz was a pioneer of diesel engines in passenger cars and the new 300D continued this trend with its use of the new five-cylinder OM617 unit. As oil prices continued to increase, buyers' attention shifted from performance to economy, and this trend was reflected in the success of these new diesel-engined models.

The engine was paired with a four-speed automatic transmission and disc brakes were placed all round. The transmission would receive revisions in 1985 along with a different torque converter in hopes of improving turbo lag and increasing acceleration at lower speeds.

The 300D was priced at $31,500, the 300CD Coupe at $35,200, and the 300TD wagon at $35,300. The range-topping 300SD was priced at nearly $40,000.

by Daniel Vaughan | Dec 2022