The new truck of Daimler-Motoren-Gesellschaft (DMG) needed ten days for its test drive in September 1923. The commercial vehicle with the new air-injection diesel engine (29 kW/40 hp at 1000 rpm) demonstrated its practical usefulness on a journey from Berlin to Stuttgart and back. The trip between the DMG factories lasted from 20 to 30 September 1923.

Bill Carroll undertook a test drive straight across the USA in 1954 in a Mercedes-Benz 190 D. The journey of 8243 kilometres (5122 miles) took the motor sport journalist from Seattle to New York. The diesel fuel for the ride across the continent cost the tester all of 32 dollars and 27 cents. “For Americans this fuel consumption is utterly sensational,” a German report on the journey said. And the journalist’s conclusion was an unequivocal recommendation to buy: “For anyone who has to drive long distances, the Mercedes-Benz 190 D is the best car.”

Mercedes-Benz bet on the publicity value of the test drive from Pacific to Atlantic. Rightly so: “The huge interest in this achievement of Bill Carroll and the general admiration for it permit us to assume, without exaggeration, that Mercedes-Benz diesel passenger cars will now continue their triumphal march through the United States.” Such was the resume of a report of the Stuttgart company on the American diesel marathon.

The 180 D wrote racing history too: in 1955, at the Mille Miglia, Mercedes-Benz dominated not only in the overall rankings, with Stirling Moss/Denis Jenkinson and Juan Manuel Fangio in the 300 SLR scoring a double victory. Stuttgart was also successful in the diesel ranking: Helmut Retter and Wolfgang Larcher won their class in a Mercedes-Benz 180 D. Their average speed was 94.6 km/h. Karl Reinhardt and Wulf Wisnewski came in second, followed by Arturo Masera and Pasquale Cardinali. In the general classification the three 180 D’s took the places 201, 214 and 220. This outstanding victory in their class impressively demonstrated the capabilities of the diesel engines in the Stuttgart-built saloons.

In 1959 Mercedes-Benz racing driver Karl Kling again showed that the diesel engine can deliver a good sporting performance: with Rainer Günzler as navigator, he won the Africa Rally over 14,045 kilometres from Algiers to Cape Town in a 190 D. His average speed: 80.6 km/h. Former Grand Prix driver Kling had succeeded the legendary Alfred Neubauer as racing manager at Mercedes-Benz – a position he held from 1956 until 1968.

A private rally team set a world record for diesels in 1959 in a Mercedes-Benz 190 SL. The small roadster was specially fitted with a revised OM 621 engine. The four-cylinder unit displaced two litres and had an output of 44 kW (60 hp). That sufficed to set a 24-hour record averaging a speed of 124.1 km/h in a 190 SL which, apart from the engine, was a stock car.

In 1961 the private rally enthusiasts repeated their attempt. This time the two-seater was thoroughly prepared to undertake the record run: all trim had been removed, and there was only a small, semicircular pane as windshield. With a 48 kW (65 hp) diesel engine under the bonnet, this time the record-breaking car averaged 142.3 km/h over five kilometres from a flying start.

11,000 kilometres from New York through the United States in a Mercedes-Benz diesel – the customer magazine Mercedes-Benz in aller Welt described this journey in 1972. The red saloon drove through big cities and across prairies, mountains and deserts on its way from coast to coast. The 220 D proved a reliable vehicle; on the Bonneville Flats in Utah it even dashed to 140 km/h for the travel diary.

A Mercedes-Benz five-cylinder diesel engine with turbocharger powered the “Dieselstar” experimental car of motor journalist Fritz B. Busch in 1975. Busch built the record-breaking vehicle on the basis of a Formula 2 racing car. On 16 November 1975, on the test track in Ehra-Lessien (Lüneburg Heath) it established a world record for diesel cars, attaining a top speed of 253.7 km/h. This was all the more remarkable in view of the fact that the existing diesel records had been established on straight-ahead stretches of the salt flats in Utah, USA. Busch, by contrast, also had to negotiate bends and brake the car on the test track. The Mercedes-Benz engine for the record attempt was fitted with an AiResearch turbocharger and a special Bosch injection pump and was slightly modified: smaller cylinder bores reduced the displacement to 2,999 cubic centimetres; to handle the high loads the unit was also provided with a nitrided crankshaft, a heavy-duty oil pump and special injection nozzles. All said and done, the engine developed 138 kW (187 hp) at 4500 rpm.

A year later, Mercedes-Benz themselves set as many as three world records for diesel cars: based on the C 111 concept car, a diesel racer took shape which was used on record-breaking runs in Nardo, Italy. Among other things Stuttgart secured itself the best times for 5000 miles (average speed 252.540 km/h), 10,000 kilometres (252.249 km/h) and 10,000 miles (251.798 km/h). In all, the C 111-II D posted 16 world records – 13 for diesel cars only, and three absolute record times. The C 111 actually originated as a test car for the rotary piston engine. But the end of the Wankel project after the second stage of development put this beautiful 1969 coupé on ice for the time being. Now the three-litre compression-ignition engine from the 240 D 3.0 gave the breathtaking sports car a new lease on life. The power unit got the racer running with 140 kW (190 hp).

Two years later a new version of the C 111 with diesel engine again took aim at a world record. This time, the record-breaking coupé was much changed from the original design: narrower, with a longer wheelbase, full fairings and extremely sophisticated aerodynamics, including tailfin. The three-litre diesel engine now developed 169 kW (230 hp) thanks to a turbocharger and intercooler; the torque of the diesel racer had been boosted to 402 Newton metres. On 30 April 1978 the car maintained an average speed of 315 km/h on the twelve-kilometre circuit at Nardo for over twelve hours. Its consumption was only about 16 litres of diesel fuel per 100 kilometres. That in itself should have earned it a world record. This time the C 111-III established nine absolute speed records, irrespective of engine type and displacement.

The diesel engine also plays an important role in the application of alternative fuels. As early as 1992, Mercedes-Benz took part in a large-scale test in Freiburg in which diesel taxis ran on rapeseed oil methyl ester instead of diesel for one whole year.

At the 2003 Tokyo Motor Show, Mercedes-Benz presented a diesel hybrid drive in the new F 500 Mind research car. The engineers combined the high-torque V8 diesel engine of the Mercedes-Benz S-Class with an electric motor arranged between the internal combustion engine and the modified automatic transmission. Pairing the two produced the most powerful, torquiest hybrid drive for rear-wheel-drive cars in 2003. While the V8 diesel developed 184 kW (250 hp) and attained a maximum torque of 560 Newton metres, the electric motor contributed an additional 50 kW (68 hp) and 300 Newton metres maximum torque. The classic division of labour between the two drive systems, depending on the situation, and the recuperation of energy from braking allowed the diesel hybrid drive to reduce fuel consumption in the European driving cycle by about 20 percent versus a comparable production vehicle.

In 2003 Mercedes-Benz presented an alternative diesel fuel. It is obtained synthetically from vegetable matter, which makes this fuel neutral with respect to carbon dioxide. The CO2 blown out the tailpipe during combustion equals exactly the amount which the plants extract from the atmosphere during the growth process.

The Vision GST 2 displayed at the North American International Auto Show in Detroit in January 2004 had a diesel hybrid drive. The Grand Sports Tourer concept car was thus more than a successor to the petrol-engined Vision GST of 2002. The pioneering hybrid consisting of a V8 diesel and an electric motor was similar to the one already used in the F 500 Mind. But now the hybrid operated in a vehicle with four-wheel drive and six-speed automatic transmission. The Vision GST 2 with diesel hybrid afforded ample dynamism and driving pleasure. The two power units with their total output of 300 kW (408 hp) propelled the concept car from standstill to 100 km/h in 6.6 seconds; the top speed was electronically limited to 250 km/h.

In Detroit in 2005 Mercedes-Benz showed the S-Class Hybrid with the so-called P1/2 drive system. It combined a powerful CDI diesel engine with two electric motors. The eight-cylinder CDI developed 191 kW (260 hp) and a maximum torque of 560 Newton metres. The two electric motors together generated 50 kW (68 hp) so that the vehicle had maximum power of 241 kW (340 hp). This made the S-Class sprint from standstill to 100 km/h in 7.6 seconds – tops for hybrid vehicles.

The V6 diesel engine in the E 320 CDI underwent an extraordinary endurance test in May 2005: three E 320 CDI production cars were put through a 30-day long-term test in Laredo, Texas, at the end of which the Mercedes-Benz diesels not only had demonstrated their reliability, but also secured three diesel world records recognised by FIA (Fédération Internationale de l’Automobile): over 100,000 kilometres (average speed 225.903 km/h), 50,000 miles (225.456 km/h) and 100,000 miles (224.823 km/h).

The world-record-setting diesel saloons again showed what they can do during a long-distance journey carried out under everyday conditions. In the summer of 2005 this test took place on highways in the south of the United States. The E 320 CDI saloons made do with an average five litres of diesel fuel per 100 kilometres on their trip through Texas, Louisiana, Mississippi, Alabama and Florida. In another six-day test drive through the USA from Las Vegas to Chicago in the summer of 2005, despite differences in altitude of altogether 23,000 metres, the E 320 CDI merely required an average 7.1 litres of diesel per 100 kilometres on the selected route.

The company launched its BlueTEC initiative for passenger cars in 2005 at the Innovation Symposium in Washington by presenting the bionic car. The bionic mobile is a research vehicle whose exterior shape makes use of the aerodynamic principles of nature. But the drive also had to be maximally environment-friendly, and so the engineers introduced the SCR technology for passenger cars in this vehicle. The engine of the bionic car is a four-cylinder turbodiesel with common rail direct injection and a displacement of two litres. This diesel engine develops 103 kW (140 hp) and consumes 4.3 litres of fuel per 100 kilometres in the standardised European driving cycle. An impressive feature is the more than 80 percent reduction in nitrogen oxides versus production vehicles. This is made possible by the first-time use of SCR (Selective Catalytic Reduction) technology in a car. In the bionic car the designers opted for AdBlue® injection; the reservoir is space-savingly accommodated in the spare wheel recess of the concept car. Its filling suffices to cover a distance equal to the servicing interval of an up-to-date diesel engine from Mercedes-Benz.

At the 2005 Frankfurt International Motor Show, Mercedes-Benz presented the S-Class S 320 BlueTEC Hybrid as a luxury-class vehicle in which the low-emission BlueTEC diesel with SCR technology provided the basis for an ultramodern hybrid drive. The electric motor of the hybrid vehicle was integrated into the drivetrain.

In 2006 Mercedes-Benz created the GTL Demonstrator test car on the basis of the
E 320 CDI. It offered extremely clean combustion thanks to a tailor-made fuel manufactured from liquefied natural gas (gas to liquid, GTL). Even without aftertreatment of the nitrogen oxides, the car achieved emission levels far below any of the current limits. However, GTL diesel in larger quantities will not be available at filling stations until some time in the future.

To further expedite the use of synthetic fuels, in March 2006 DaimlerChrysler, Renault, Royal Dutch Shell, Sasol Chevron and Volkswagen formed the “Alliance for Synthetic Fuels in Europe” (ASFE). The synthetic fuels include SunDiesel, obtained from organic matter (biomass to liquid, BTL), and synthetic GTL diesel, obtained from natural gas. Synthetic fuels are already contributing to the reduction of emissions. The aim is to better utilise this potential with more advanced technology.

At the Challenge Bibendum in Paris, besides other vehicles Mercedes-Benz showed an E-Class which operates on the BTL fuel SunDiesel. The use of such biogenic fuels causes no additional carbon dioxide to be released, as combustion produces only as much carbon dioxide as was absorbed by the plants during their growth. BTL diesel thus improves the CO2 balance by as much as 90 percent compared with conventional diesel fuel. And there are no technical limits to the use of SunDiesel.

In addition, in Paris the company displayed a concept car – the smart fortwo cdi hybrid – in which a diesel engine and electric motor work together. The consumption of the smart fortwo cdi hybrid is expected to be about 2.9 litres of diesel per 100 kilometres, obtained with a sprightly driving style.

In the “E-Class Experience Paris–Beijing”, a long-distance journey covering 13,600 kilometres, undertaken by a fleet of 36 Mercedes-Benz E-Class Saloons, three 320 BlueTEC models also took part in late autumn 2006. The 26-day run was in memory of the legendary long journey of 1907 that started out in the opposite direction, from Beijing to Paris. Some 50,000 applicants wanted to take part in the modern-day journey – 360 persons from 35 countries were selected and drove sections of the route with different lengths on the way from France to China.

The unique long-distance trip from Europe to Asia led through France, Germany, Poland, Lithuania, Latvia, Estonia, Russia and Kazakhstan to China. The daily legs were up to 750 kilometres long and had to be negotiated at low temperatures, in ice, snow and with short daylight periods, travelling through partly almost impassable terrain and crossing mountain passes up to 2900 metres high. On 17 November the vehicles arrived in the Chinese capital. The three E 320 BlueTEC impressively demonstrated the potential of advanced diesel technology during the journey.