Every once in a while, a car model appears that’s so advanced for its time that it sets the direction for the entire automotive industry in the years to come. We’re talking about cars like the Ford Model T, which popularized mass production, the VW Beetle, which made affordable transport global, the Toyota Prius, which set the standard for hybrid vehicles, or the Tesla Model S, which proved that EVs can be viable.An often overlooked car that totally deserves to be on this list is the first-generation Mercedes-Benz S-Class, better known by its W116 codename. Built between 1972 and 1981, the W116 was the brand’s first full-size luxury sedan officially given the S-Class moniker, and its influence on Mercedes-Benz and the auto industry as a whole cannot be overstated.At the pinnacle of the W116 lineup stood one of the most impressive performance luxury sedans ever made, the iconic Mercedes-Benz 450 SEL 6.9, or the Mercedes-Benz 6.9 as it was marketed in the United States. This legendary car was so sophisticated when it launched in 1975 that it wouldn’t feel out of place half a century later. Here’s why. The First High-Performance Mercedes-Benz S-Class Mercedes-Benz In 1975, when the 450 SEL 6.9 launched in Europe, then independent racing outfit AMG had only been around for a few years and had just started to make a name for itself in motorsport, taking second place overall at the 1971 24 Hours of Spa race with the heavily modified Mercedes-Benz 300 SEL 6.8 AMG ‘Red Pig’, which also won its class at the event.While AMG started offering aftermarket tuning kits for Mercedes-Benz vehicles shortly after that, the first AMG road car officially sanctioned by the automaker would arrive two decades later, when a cooperation between the two companies resulted in the launch of the C 36 AMG in 1993.Mercedes-Benz Obviously, Mercedes-Benz did build performance variants of its sedans long before that, starting with the 300 SEL 6.3 launched in 1968. This car is widely considered the ancestor of all Mercedes-Benz high-performance sedans, including the AMG line. But the accolade of being the very first high-performance S-Class belongs to the W116-based 450 SEL 6.9, a bonkers luxury sedan that combined breathtaking performance with opulence in unprecedented fashion.Envisioned as the ultimate successor to the 300 SEL 6.3, the 450 SEL 6.9 received a bored-out, 6.8-liter dry-sump version of the legendary M100 V8 engine from the Mercedes-Benz 600 flagship, which worked wonders combined with the state-of-the-art, long-wheelbase W116 chassis. Mercedes wanted to build a luxury sedan that could cruise at high speeds while providing an incredibly smooth ride, and the 450 SEL 6.9 delivered, earning the nickname of “King of the Autobahn” in the process. This Old Merc Is Still Faster Than Many Modern Family Cars Mecum Hooked to a 3-speed automatic transmission adapted to handle the increased output and torque, the tweaked V8 delivered 282 hp at 4,250 rpm and 405 lb-ft of torque at 3,000 rpm in European specification, enabling a top speed of 140 mph and a 0-60 time of 7.4 seconds – though some independent tests and sources reported it to be as quick as 7.1 seconds. Those were impressive numbers for a massive luxury sedan that tipped the scales at 4,376 lbs.The 450 SEL 6.9 became the world’s fastest, most powerful production sedan, and it held on to that title until production stopped in 1980. It’s still quick today and can definitely keep up with modern traffic.Interestingly, the 450 SEL 6.9 was available in two different variants, one for Europe and the rest of the world and a modified one for North America. Mercedes-Benz was forced to engineer a different U.S. specification to comply with America’s strict emissions and safety regulations of the 1970s.Mercedes-Benz For starters, the engine featured a lower 8.0:1 compression ratio compared to the Euro model’s 8.8:1, a catalytic converter for unleaded fuel and added smog equipment. U.S. models also had different fuel distributors (K-Jetronic), ignition distributors, manifolds and camshaft timing.All these changes stole power from the engine, which was rated at 250 hp and 360 lb-ft of torque in the USA. That made the Mercedes-Benz 6.9 slightly slower than its European sibling, although it was still a force to be reckoned with.Other significant differences between the two versions were safety-driven styling changes displayed by the U.S. model, which featured the bulky U.S.-spec bumpers and round sealed-beam headlights to comply with federal regulations. For some people, these changes kind of ruined the 450 SEL 6.9’s stylish looks, but if you’re in the market for one, don’t worry: you can always buy a Euro-spec model and import it legally, as the 25-year rule exempts it from meeting EPA emission standards and DOT safety regulations. The Mercedes-Benz 450 SEL Was The Most Advanced Production Sedan Of Its Time Mercedes-BenzAs mentioned earlier, the Mercedes-Benz 450 SEL 6.9 is the pinnacle of the first-generation S-Class, a technological tour de force in itself. The W116 shaped the brand for decades to come, both in terms of design and technological advancements.The luxury sedan pioneered critical safety and engineering tech that would become the norm later on. Those included the world’s first fully electronic multi-channel, four-wheel ABS (introduced as an option in 1978), crumple zones around the rigid passenger cell, a fuel tank placed over the rear axle rather than in the rear to protect it from rear collision damage, as well as large, dirt-repelling taillights and side windows designed to remain clean in wet weather.The interior was also engineered with passenger safety in mind, as the four-spoke safety steering wheel, the padded dashboard, and recessed switches were designed to minimize injury in accidents.Mecum And the innovations did not end there. The W116 made history in 1977 when it became the first-ever passenger car to feature a turbodiesel engine as the 300 SD, a model developed specifically for North America to meet strict U.S. Corporate Average Fuel Economy (CAFE) regulations following the 1970s oil crisis. This allowed Mercedes to continue selling high-performance V8 models in North America, such as the 450 SEL 6.9. The 300 SD featured a 3.0-liter five-cylinder turbocharged diesel engine (OM617) that produced just 110 hp and 168 lb-ft of torque. This made it really slow, barely hitting 100 mph and doing 0–60 in 14 seconds on a good day.Back to the 450 SEL 6.9, its top-dog status was reinforced not only by the mighty powertrain, but also by its exclusive suspension, a sophisticated hydropneumatic self-leveling suspension that incorporated hydraulic struts and nitrogen-filled spheres instead of traditional springs or shock absorbers. Mercedes-Benz licensed this solution from Citroën but made it more robust and fail-safe, adding rubber emergency dampers that allowed the car to be driven if the hydraulic system stopped working. The German automaker also tuned the suspension for better high-speed handling and stability, which resulted in a firmer ride than the extreme plushness offered by Citroën but still remarkably comfortable. A Highly Valued Collectible Mercedes-Benz If you’re interested in buying a Mercedes-Benz 450 SEL 6.9 in 2026, you should know that values are on the rise given the model’s rarity and historical significance. The carmaker built 7,380 units between 1975 and 1981, but only 1,816 of those were officially sold in the United States. The Classic.com Market Benchmark lists the 450 SEL 6.9 at around $35,000, but that’s just the estimate for an average condition example.Low-mileage cars in tip-top shape can go as high as $100,000 (the highest-ever transaction price for the 450 SEL 6.9, set in November 2025 on Bring A Trailer), while examples in poor condition with many miles can be as cheap as $10,000 (the minimum transaction price over the past year monitored by Classic.com). Obviously, a lot depends on the condition of the car and how well it was looked after, as the 6.9 is known to be quite problematic and very expensive to maintain due to its sophisticated technology and aging components.So, is it good as an investment vehicle? Since it’s relatively rare and highly significant, the 450 SEL 6.9 clearly has collector appeal, especially well-maintained, well-documented examples in original condition. From March 2025 to December 2025, the average transaction price has gone up from $15,850 to $40,000, a clear sign that values are on the rise.Sources: Mercedes-Benz, Classic.com