The Mercedes-Benz 240D was perhaps the most durable diesel-powered Mercedes ever to hit the market. It had a successful production run from 1974 to 1985 with 454,780 units sold worldwide. In 1981 alone, 73,162 240Ds left showrooms. At its launch, Mercedes marketed the 240D model as its most luxurious. It was also the most expensive model at $7,712 ($33,707 in 2010 dollars.)
Mercedes-Benz has a long history of producing diesel-powered passenger cars and trucks. The 240D's origins date to 1934 when Mercedes engineers modified a gasoline-powered commercial in-line six-cylinder engine into a 2.6-liter four-cylinder diesel with a five-bearing crankshaft and overhead valves. The result was the 260D six-seat Pullman passenger car launched in 1936 with a maximum range of 250 miles. The 260D became an instant hit with cab companies for its exceptional fuel efficiency. By the end of 1936, a diesel-powered 4/5-seat saloon, or sedan, and 4/5-seat convertible also became available. Mercedes introduced a fully-synchronized four-speed manual transmission to boost fuel efficiency. Nearly 2,000 260D models left the factory between 1936 and 1940.
Mercedes had phenomenal success with its diesel passenger cars. The 180D in the 1950s sold so well that it stole the larger 190D's thunder when it arrived in 1955. In 1958, 26,000 180Ds left the factory, and another 10,000 in 1959. The 190D displaced 1897 cc and generated 55 horsepower. In the 190D, Mercedes replaced the pushrod system with an overhead cam and gave the engine a shorter stroke that helped increase endurance. The 190D cemented Mercedes' dominance in the diesel passenger-car market. By 1974, when the 240D arrived, the automaker had produced more than 1 million diesel-powered cars, which represented about 35 percent of Mercedes' total passenger-car production.
Mercedes placed the 240D on the W115 chassis. It cost four times more than the typical European or U.S.-built automobile and featured such luxuries as cruise control, heated leather seats and a power sunroof, which were rare amenities for the 1970s. The 240D had a 2.4-liter four-cylinder diesel engine that initially developed 55 horsepower and was matched with either a four-speed manual or three-speed automatic. The engine featured a 3.58-inch bore, 3.64-inch stroke and a 21-to-1 compression ratio. In the 1978 model, the 240D generated 72 horsepower and 101 foot-pounds of torque. For a diesel-powered car weighing more than 3,300 lbs., it received high marks in automotive reviews for clocking 24.7 seconds in 0 to 60 mph tests. It had a top speed of 83 mph. By today's standards, its overall speed performance is poor.
The 240D carried the legacy of the 1930s 260D version as a popular taxi. Used primarily in Eastern Europe, the Middle East and African countries, vintage 240Ds were still plying the streets as taxis more than 25 years after production ceased. It's not unusual for a 240D to go more than 400,000 miles without a major overhaul. Mercedes stopped exporting the 240D to the United States in 1983 and ended production in Germany in 1985.
