It has the distinction of being the most popular Mercedes-Benz flagship of all time: The internally designated 126-chassis Sonderklasse (Special-Class, S-Class for short) was sold from the late 1970s through the early 1990s, and to many, it represents the archetypal conservative German executive sedan. The Stuttgart-based automaker recently recognized the 40th anniversary of the 126 S-Class, which debuted in September 1979 at the Frankfurt Motor Show. That four-door sedan replaced the long-serving 116-chassis that would spawn the famous 450 SEL 6.9. The W126, with styling penned under the masterful Bruno Sacco, was a clever evolution of the established theme, simplified, strengthened, and interpreted through the wind tunnel with a resulting period-excellent Cd of 0.36, representing a five-tenths improvement over its predecessor.
This new S-Class sedan could be had in regular (115.5-inch) and long-wheelbase (121-inch) forms, propelled by gasoline- or diesel-fueled engines. The lighter, stiffer bodyshell with neatly integrated bumpers offered improved impact resistance, while the body’s aerodynamics and the efficiency of a new four-speed automatic transmission led to a 10-percent increase in fuel economy. Suspension was fully independent, with a multi-link rear, and anti-lock brakes were an innovative standard fitment, carried over from the W116.
S-Class occupants would now enjoy an effective new climate control system, and in 1981, the premiere of Mercedes-Benz’s new driver’s airbag; the front passenger could benefit from an available seatbelt pretensioner; these items would become available in all Mercedes-Benzes the following year.
1981 also marked the launch of the new S-Class coupe, internally coded C126, the SEC. Replacing the polarizing SLC, this four-passenger pillarless hardtop, riding on a shortened 112.2-inch wheelbase, offered classical proportions and incredibly elegant styling, with an athletic air that was reinforced by an SL-style grille with a large, central star. Special features included four individual bucket seats, power-operated front seatbelt presenters, and unique aerodynamic exterior door handle fairings designed to keep the handle grips clean.
Mercedes updated and improved the S-Class through the 1980s, adding safety, performance, and comfort features that included available traction control, a front-passenger airbag, an automatic locking differential, and an electrically adjustable steering column.
A mild refresh brought notable revisions for the 1986 model year, and among them were 1-inch-larger (now 15-inch) wheels covering upsized brakes, flush headlamps, and smooth, extended lower body cladding. The interior remained simple, ergonomically correct, and beautifully made, delightfully housing absolutely none of the distracting gee-whiz features today’s buyers seem to demand. It also marked the introduction of the 5.5-liter V-8 in the 560 series cars.
During the 126’s tenure, U.S. buyers could purchase their S-Class sedans with a 3.0-liter inline-six, a 3.0-liter inline-five turbodiesel, a 3.0-liter inline-six turbodiesel, a 3.5-liter line-six turbodiesel, a 3.8-liter V-8, a 4.2-liter V-8, a 5.0-liter V-8, or a 5.6-liter V-8 under the hood. SECs could only be had here with eight cylinders, as a 380, 500, or 560.
The second half of the 126’s run went by with only minor year to year changes, demonstrating Mercedes-Benz’s confidence in a winning formula. A passenger’s-side airbag came in 1989, and traction control, known as ASR (Acceleration Slip Reduction) was optional for the final 1991 model year.
Mercedes-Benz reported that, at the end of the 12-year 126-chassis production run, a total of 818,036 four-door sedans were built; of those, 97,546 were diesel-fueled. Additionally, the C126 SEC’s 10-year production span yielded 74,060 examples.
Happy birthday, Mercedes-Benz 126. You don’t look a day over 28.