This Was The First Automobile Ever Powered By A Diesel Engine

When most individuals consider diesel engines, they often picture heavy-duty trucks and locomotives — or they could recall Volkswagen’s Dieselgate scandal – but diesel power actually made its passenger automotive debut nearly a century ago. While the 1936 Mercedes-Benz 260 D is commonly credited as the primary production automotive with a diesel engine, the complete story goes back a bit farther and includes earlier prototypes — plus a surprise appearance from a French automaker.

The diesel engine takes its moniker from its inventor, Rudolf Diesel, who patented his first-of-its-kind compression ignition engine within the Eighteen Nineties. Unlike gasoline engines, which use spark plugs to ignite air and fuel inside the combustion chamber, diesel engines depend on compressing air to intense pressures and temperatures before injecting fuel. The resulting combustion shouldn’t be only powerful, but highly efficient. These qualities made it ideal for each industrial and industrial use.

Early applications of diesel power were seen in ships, trains, and factories because these massive engines were far too heavy for the compact personal vehicles of the time. It wasn’t until the early twentieth century that automakers began to significantly experiment with smaller, more roadworthy versions.

Mercedes-Benz unveiled the 260 D – internally designated the W 138 – on the Berlin Motor Show within the spring of 1936. It was a pullman landaulet model that might comfortably seat six that was powered by a 2.6-liter four-cylinder diesel engine and boasting a modest 45 horsepower. It wasn’t showy or particularly powerful, however it was efficient, reliable, and consumed less fuel than its gas-powered counterparts.

Mercedes put it into full production in September of that 12 months, selling nearly 2,000 units between its introduction and December 1940. They introduced three sedan versions along with the flagship pullman, which became particularly popular with taxi operators who were highly appreciative of its fuel efficiency. The 260 D’s significance is not that it was the very first diesel powered vehicle, but quite that it was the primary diesel-powered passenger automotive produced at scale and marketed to on a regular basis drivers. Its OM138 engine set an ordinary for durability and fuel economy that will turn into the hallmark of diesel engines for years.

Still, simply because Mercedes-Benz made it to production and sale to most of the people first doesn’t mean that French automaker Citroën doesn’t deserve its justifiable share of the credit for the diesel engine’s launch. Three years before the debut of the 260 D, Citroën fitted considered one of their 7U Rosalie models with a diesel engine, and built a handful of successful prototypes based on the 7U platform. While these cars weren’t available to the general public or produced in quantity, they were drivable and road-tested.

So while most historians acknowledge that Mercedes-Benz deserves credit for being the primary to really produce a diesel passenger automotive at scale, Citroën rightly deserves recognition for showing that diesel wasn’t just an idea for tractors, trucks, and tankers. It provided a glimpse of the longer term where diesel engines may very well be refined, road-worthy, and at home in a consumer vehicle.

Though diesel passenger cars never really took off within the U.S. market, they became staples across Europe, particularly within the a long time post WWII. Mercedes-Benz’ 260 D and its subsequent iterations laid the groundwork for future diesel cars produced by other European automakers like Fiat and Volkswagen. In 1978, Mercedes-Benz was first again with its introduction of the turbodiesel 300 CD and 300SD with turbocharged engines delivering much more refinement and performance.

Today, diesel engines remain ubiquitous in industrial applications — trucking, agricultural vehicles, and shipping. Nevertheless, these engines have faced scrutiny in recent times within the face of tighter and tighter emissions regulations and the rise of EVs. We do not yet know exactly what the longer term holds for restrictions on diesel engines, as mandates are largely affected by the shifting political tides, but its clear that they are here to remain in some form or fashion. 

The 1936 Mercedes-Benz 260 D wasn’t fast — and definitely couldn’t haul heavy loads — however it did prove that diesel could work in a passenger automotive, paving the best way for a brand new era of automotive engineering. For that, it earns its place within the diesel hall of fame, sharing the highlight with the Citroën that quietly held the door open for its arrival.