(May 7, 2013) MONTVALE, N.J. — The diesel engine has come a long way since compression ignition was first demonstrated by German engineer Rudolf Diesel in 1893. And no other manufacturer has played a greater role in its development for automotive applications than Mercedes-Benz.

Modern diesel engines are clean, smooth-running, and above all, highly efficient. In Europe, around 50 percent of passenger cars run on diesel engines, and calculations indicate that if just one-third of American cars ran on diesel, the country could massively reduce its dependence on foreign oil.

Following the merger in 1926 of Daimler Motoren Gesellschaft and Benz & Cie., the new Daimler-Benz AG designed a six-cylinder inline diesel for heavy trucks, marking the start of a development process that would have lasting impact on the automotive industry. However, it would take almost 10 years of testing and development for Mercedes-Benz engineers to create a diesel engine that they felt was good enough to run in a passenger car bearing the Mercedes-Benz badge.

The 1936 260D featured a 2.6-liter four-cylinder diesel engine with overhead valves and a maximum output of 45 horsepower. It achieved fuel mileage of almost 25 mpg — a stunning figure at the time considering that the 260D's gasoline equivalent managed just 18 mpg.

Mercedes-Benz diesel power in the U.S. began in 1949 with the 170D (38 hp, 71 lb-ft) featuring a 1.7-liter inline four. Its successor — the 1954 180D (40 hp, 75 lb-ft) — came with the groundbreaking "Ponton" unibody design. In 1958, Mercedes- Benz introduced the 190D (50 hp, 80 lb-ft) in the U.S., featuring the all-new, 1.9- liter four-cylinder engine. For the 1966, the 190D with the "Fintail" body was renamed the 200D (55 hp, 87 lb-ft) and, for the first time, a Mercedes-Benz diesel came with an automatic transmission. In 1968 the 200D was followed by the 2.2-liter 220D (60 hp, 93 lb-ft) and then the 2.4-liter 1974MY 240D (65 hp, 101 lb-ft).

Proliferation in the 1970s

The oil crisis of 1973 precipitated a sudden scramble to reduce fuel consumption that saw demand for diesel soar. As the leading diesel manufacturer, Mercedes- Benz bolstered its diesel range with the 1975 300D (80 hp, 127 lb-ft), featuring the world's first five-cylinder diesel engine. Its successors came in 1977 as the four-cylinder 240D and the 300D inline five with 80 hp, later increased to 88 hp.

The late seventies and early eighties was a boom time for Mercedes-Benz diesel. U.S.-specific models included the world's first diesel-powered coupe, the 1978 300CD, as well as the first-ever diesel S-Class, the 300SD. What made the 300SD even more remarkable was the introduction of turbocharging with the brand-new 3.0-liter five-cylinder turbodiesel. The new turbocharged engine generated 121 hp and 170 lb-ft of torque and achieved 0-60 mph in a respectable 14 seconds.

With the 300CD Turbodiesel, the 300D Turbodiesel and the 300SD Turbodiesel as U.S.-only variants, Mercedes-Benz was producing more market-specific models for the U.S. than for any other market. By 1982, almost 80 percent of Mercedes-Benz USA's sales were diesels.

For the 1984 model year, MBUSA further expanded its diesel lineup to include the "Baby Benz" — the predecessor to the C-Class. Initially launched with the four cylinder engine, the 190D (73 hp, 96 lb-ft) was superseded by the 1986 2.5-liter inline five (90 hp, 114 lb-ft) and joined in 1987 by a turbocharged version (122 hp, 166 lb-ft).

1986 brought another U.S.-only S-Class diesel called the 300SDL (150 hp, 201 lb-ft). The turbocharged inline five-cylinder engine had grown to an inline six. The subsequent 1990MY 350SDL (136 hp, 229 lb-ft), also made specifically for export to the U.S., was equipped with the 3.5-liter inline six turbodiesel. In the full-size class, the 300D 2.5-liter turbo was superseded in 1995 by the E300D and then the E300DT with its mighty 174 hp and 244 ft-lb of torque.

The Mercedes-Benz diesel station wagon carved out an impressive niche during the eighties. The first to make its mark was the 1980 300TD with the 3.0-liter inline five naturally aspirated engine. A turbocharged version followed in 1981 and was then carried over to the next generation.

Modern Era

For the 2007 Mercedes-Benz replaced its successful diesel inline six format with the V6 layout, which also marked the introduction in the U.S. of common-rail direct injection with 29,000 psi. The CDI engine also brought the first SUVs with diesel power to U.S. shores in the 2007 ML320 CDI (215 hp, 398 lb-ft), GL320 CDI (215 hp, 398 lb-ft) and the R320 CDI (215 hp, 398 lb-ft).

Also in the 2007 model year, Mercedes-Benz again broke new ground in diesel technology and selected the U.S. for the global premiere of its pioneering BlueTEC diesel technology. The E320 BlueTEC (210 hp, 398 lb-ft) was voted 2007 World Green Car for its exceptionally low emissions. It met the world's most demanding NOx and particulate limits set by the BIN5 standard and once more confirmed Mercedes-Benz as the premiere brand for diesel passenger vehicles in all fifty states.

A barrage of BlueTEC SUVs followed in 2009, all featuring the next phase of BlueTEC technology with AdBlue exhaust gas after-treatment. The ML320 BlueTEC, GL320 BlueTEC and R320 BlueTEC all came with the same V6 turbodiesel as the E320 BlueTEC, producing 210 hp and a maximum torque of 398 lb-ft. Combined fuel consumption for the popular ML320 BlueTEC was 20 mpg, while for the GL320 BlueTEC it was 19 mpg, making it the most fuel-efficient full-size SUV on the market. In 2010, commercial vehicles returned to Mercedes-Benz USA with the introduction of the BlueTEC-equipped Sprinter Van.

The launch of the 2013 GLK250 BlueTEC 4MATIC marks the return of a Mercedes-Benz four-cylinder diesel to the U.S. after an absence of nearly three decades. Mercedes-Benz already has the most extensive diesel lineup of any automaker in the U.S. today, and this fall marks the arrival of its second four-cylinder diesel in the 2014 E250 BlueTEC.