In 1973, Mercedes-Benz introduced the Mercedes W116 line, the first to be officially called the S-Class. Produced from 1972 through 1979, the Mercedes W116 series featured a four-wheel independent suspension and disc brakes. The Mercedes 280, 350, and 450 (4.5L version) models featured SE and SEL versions. Production of the Mercedes W116 totaled 473,035 units. This was a groundbreaking sedan for Mercedes-Benz, and for the first time in the company history, the car had an obvious, blatant and outward emphasis on safety placed above a pure styling viewpoint. The overall design incorporated numerous safety features developed from the "safety research vehicles" in the mid-to-late 1960s to the very early 1970s.
These safety features were all newly-introduced passenger-car "firsts" on a production vehicle: padded door trim around the windows, heavily padded steering wheel (later to be replaced by an airbag with the Mercedes-Benz abbreviation of SRS standing for the English-language term Supplemental Restraint System), more comprehensive safety padding on the dashboard and around the interior, dual asymmetric windshield wipers, headrests with a center depression to locate the occupant's head in a more central position during a rear impact, a rain-water management system to improve visibility consisting of deep channels on both sides of the windshield and flowing into deeply channeled rain gutters, including similar designs on the side mirrors, rounded body shapes along the edges, such as the tops of the front fenders, etc., designed to ameliorate pedestrian injuries, ribbed rear taillamp lenses which would remain clearer of dirt on the recessed areas, an easy-to-access first aid kit stowed in a recessed compartment on the rear parcel shelf prominently labeled with the universally-recognized "cross" symbol which represents "first aid", and several other subtle safety features related to both active and passive safety.
The Mercedes W116 models were large luxury sedans. The Mercedes W116 was larger on the outside than the Mercedes W108/W109 series it replaced, but had similar interior capacity, as the additional bulk was driven by several new and aforementioned engineering developments on car safety and occupant protection in a crash. The Mercedes W116 introduced other improved passive safety features into the vehicle design, including a strengthened vehicle occupant shell. It was one of the first cars to be available with ABS, a driver's airbag supplemental restraint system (but not available at the vehicle's initial launch), and the first appearance of a turbocharger for the diesel engine.
The Mercedes 450SE, then the most powerful model in the Mercedes W116 lineup, was awarded European Car of the Year in 1974. At the New England Auto Show in 1972 held in the fall season in Boston, the Munroney Label (window sticker) of a 1973 Mercedes 450SE was right at $13,000. 1973 was the first model year of the Mercedes W116 for the US market. Starting in 1975, the Mercedes W116 was upgraded with a new fuel injection system in order to comply with revised exhaust emission standards in European markets. A slight power reduction was a result of this update, but in 1978, a series of further engine upgrades restored original performance levels under the new fuel injection systems.
Engines
With the Mercedes W116 models, the V8-engines of the Mercedes 350/450 SE/SEL models were now regular options. Due to the oil crisis, fuel efficiency was the major concern for the engineers, yet they still added also the high-performance, limited-production 450 SEL 6.9. This 8-cylinder model, affectionately referred to as simply "the 6.9", boasted the largest engine installed in a postwar Mercedes-Benz up to that time. Every 450 SEL 6.9 featured a self-leveling hydropneumatic suspension, and offered the ABS anti-lock braking system as an option from 1978 onwards. Also, in the United States and Canada only, Mercedes-Benz introduced the economical but powerful 3.0 liter 5-cylinder turbodiesel in 1978, sold as the Mercedes 300SD.