• 1894: Daimler engines take 1st and 4th places in the world’s first automobile competition
• Epoch-making Grand Prix wins in 1908 and 1914
• Supercharger era begins in 1922
The internal combustion engine-powered automobile was just eight years old when it faced the challenge of the first public competition. At this event held in France in 1894 the first four places went to vehicles equipped with engines built according to the Daimler system. This first official trial of strength for cars was sponsored by the Parisian newspaper Le Petit Journal and covered the 126 kilometres from Paris to Rouen. The selection process was stringent: of the 102 vehicles that applied for a starting place, 21 were finally authorised to race and only 15 cars reached the finish line. Of these, nine were equipped with a Daimler engine manufactured under licence, including the first four finishers in the internal combustion engine category, which were equipped with two-cylinder V engines from Panhard-Levassor. These 2.6 kW engines provided an average speed of 20.5 km/h.
First place in the 1894 event was shared by a car of the Peugeot brothers and a Panhard-Levassor car. The V engine of the Peugeot Vis-à-vis had two cylinders banked at a 17 degree angle. Vertically installed underneath the bench seat, the engine had a displacement of 974 cubic centimetres and developed 2.6 kW at 620 rpm. Two more Peugeots took third and fourth place and a Roger-Benz with an output of 3.7 kW finished fifth. In the years that followed, a range of cars powered by Daimler engines won numerous victories and substantiated the excellent reputation of state-of-the-art technology from Germany. Companies were quick to recognise the publicity value of such racing successes and began to turn them to good account for selling their vehicles.
At that time there was no clear distinction between the car as a means of transport and as a sports vehicle. At first the car’s inventors envisaged the motor vehicle mainly in terms of its pragmatic utility. But the idea of pitting these motorised vehicles against each other in open competitions was not slow to emerge. Improvements to competition cars fed back directly into series production – if indeed the small production runs, mostly built by hand, can be so described. Hence the first competition in 1894 not only marked the beginning of motor sport in the modern sense, but also the start of the rapid pace of development in automobile construction. As a result, technical developments in motor racing barely differed from production car development, apart from a few details, until well into the first third of the 20th century.
The first competition for automobiles with internal combustion engines can also be seen as a farewell to the older steam technology. A De-Dion-Bouton steam car was actually the first vehicle in the field across the finish line in 1894, but the vehicle was incredibly heavy and did not comply with the weight restrictions for the competition, and its achievement was rewarded with only second place. In view of the rapid improvements in the performance of cars with Otto cycle engines, races between steam-powered vehicles and cars with internal combustion engines became increasingly rare in the following years. Whereas steam cars of various designs were still allowed to participate in the 1894 event, cars with other drive systems – electric cars, hydromobiles and vehicles with compressed air, gas, or electro-pneumatic drive systems – were not permitted to enter.
Among the thousands of people who followed the race were Gottlieb Daimler and his son Paul, who later described his impressions of the day in these words: ‘On the early morning of race day my father and I were not far from Porte Maillot near Paris. Huge crowds came to witness what was a unique spectacle in those days, cars lining up at the start of a race. The shape, size and design of all these racing cars were very different; heavy steam cars with trailers, veritable powerhouses, were competing against the lightest steam-powered three-wheelers, and these in turn with petrol-powered cars; all had come with the same aim: to be the first to reach Rouen and to arrive back in Paris at Porte Maillot.
We ourselves (i.e. Paul and Gottlieb Daimler) accompanied the race in our car. The different vehicle types made a curious impression; we watched the boilermen on the heavy steamers, dripping with perspiration and covered with soot, working hard to put on fuel; we could see how the drivers of the small steam-powered three-wheelers kept a watchful eye on the pressure and water level in the small, skilfully fitted tubular boilers and regulated the oil firing; and in contrast to that we saw the drivers of the petrol and paraffin-powered cars sitting calmly in the driver’s seat, operating a lever now and again, as if they were simply out for a pleasure trip. It was a very strange picture, and an unforgettable one for me ...’
The following year it was a similar picture in the Paris–Bordeaux–Paris race over 1192 kilometres, regarded as the first true car race. Among the first eight finishers were six cars equipped with Panhard-Levassor engines built under Daimler licence, and two Benz vehicles. In 1896, cars with Daimler engines then scored a triple victory on the Paris–Marseille–Paris run over 1728 kilometres at an average speed of 25.2 km/h. Daimler engines continued to dominate races in France, be it in the Paris–Dieppe race (triple victory) and Paris–Trouville race (victory) in 1897, or one year later in the Marseille–Nice (triple victory) and Paris–Bordeaux races (winner René de Knyff).
1898: Daimler cars notch up victories in their own right
However, Daimler-Motoren-Gesellschaft was not satisfied with being a top engine builder – it wanted to win races with its own vehicles. The Stuttgart firm duly succeeded in doing this at the Berlin–Leipzig–Berlin race (25-27 May 1898), won by a Daimler automobile. Friedrich Greiner was at the wheel, completing the race with an average speed of 24.3 km/h. Shortly before this, also in May 1898, the first-ever German car race was staged, from Berlin to Potsdam and back. In his chronicle of the racing history of Mercedes-Benz, automotive historian Karl Eric Ludvigsen provides a vivid description of the advent of motor sport on German soil: ‘A few inquisitive souls had turned up to see the departure of thirteen chugging, rattling horseless carriages with their own eyes. It was the start of the first automobile driving competition in the German Empire. The cars roared off down the rutted main road in the direction of Potsdam – the town chosen as the turning point, from where the participants would set off on the return trip. Potsdam was also the residence of one of the first German promoters of motorisation – Kaiser Wilhelm II. The 54-kilometre drive was also historic for another reason, as the first time Daimler and Benz automobiles had lined up together at the start.’
There were also various other events. The first Dolomites race around Bolzano in August 1898 was won by Wilhelm Bauer and Wilhelm Werner in their Daimler Viktoria car. The race, dominated by the 5.5 kW vehicle with a two-cylinder engine, is regarded as the first properly supervised long-distance car race through the Alps – and again it was Daimler that made its mark in the early history of motor sport. A year later Wilhelm Bauer also won the Nice–Colomars–Tourettes–Magagnone–Nice touring race for two-seaters, one of the events held during Nice Week. Arthur de Rothschild finished second. Both drivers drove a Daimler Phoenix model with an output of 8.8 kW. Wilhelm Werner in a 12 hp Daimler Phoenix racing car crowned the success of the German brand with a win in the four-seater car class.
Also in 1899, Daimler cars scored a double victory in their class in the first Semmering race. The driver of the winning vehicle, a 12 hp Daimler Phoenix, was Emil Jellinek, originally from Vienna, a businessman and Austrian Consul General, who went on to become a famous name in motor sport circles. He ordered his first Daimler car in 1897. In 1898, he bought the world’s first two road vehicles equipped with four-cylinder engines (8 hp Daimler Phoenix models), now mounted at the front. But as well as driving Daimler cars, he also sold them, supplying DMG automobiles from Stuttgart mainly to members of the upper classes, and with rapidly increasing success. In 1899, DMG delivered ten cars to Jellinek, and in 1900 he took 29. Meanwhile, he was calling for increasingly powerful and faster cars which he also personally entered in racing events. His drives at Nice Week under the pseudonym ‘Monsieur Mercédès’ were to become the stuff of legend. Jellinek borrowed the name from his daughter Mercedes, born in 1889.
1900: Beginning of the Mercedes era
In April 1900, ‘Mercedes’ became the product designation when Jellinek and DMG signed an agreement on the sale of cars and engines and Daimler promised to develop a new engine that was to be called ‘Daimler-Mercedes’. A short time later, within just a few weeks, Jellinek ordered from DMG a total of 72 cars of varying engine outputs, which was a gigantic order in 1900 terms. The first car equipped with the new engine, a 35 hp Mercedes racing car, was delivered on 22 December 1900.
This first Mercedes, designed like many vehicles before it by Wilhelm Maybach, the chief design engineer of DMG, marked an early high point in the development of the modern car. The dynamic evolution from carriage-like motor vehicle to an automobile with a design idiom of its own had been foreshadowed for some time. In this racing car, however, Maybach succeeded in realising a truly pioneering concept. The automobile had a 5.9-litre front-mounted four-cylinder engine, whose formidable 26 kW output permitted a top speed of no less than 100 km/h. Other features included a low centre of gravity, a pressed steel frame, a lightweight engine design and the revolutionary honeycomb radiator.
The Mercedes automobiles dominated the Nice Week of March 1901. Wilhelm Werner won the Nice–Salon–Nice race over 392 kilometres at an average speed of 58.1 km/h, and the Nice–La Turbie Hillclimb over 15.5 kilometres was also won by Werner in the two-seater racing car category (top speed 86 km/h, average 51.4 km/h), followed by Lemaitre in a second 35 hp Mercedes.
In addition, in a record-breaking attempt during Nice Week Claude Lorraine-Barrow attained an average speed of 79.7 km/h over the standing start mile, setting a new world record. The Daimler racing cars were victorious in almost all disciplines, guaranteeing Jellinek – and therefore DMG – extraordinary publicity and resulting in a corresponding rise in demand.
The success of the new car impressed experts and the general public alike. Paul Meyan, general secretary of the French Automobile Club, acknowledged the rising supremacy of the German automobile brand Mercedes on the courses that had long been dominated by French makes: ‘Nous sommes entrés dans l’ère Mercédès’ (‘We have entered the Mercedes era’), he wrote after Nice Week of 1901.
1903: Gordon Bennett Trophy race victory in Ireland
By 1902, the 35 hp Mercedes racing and touring car had already been replaced by the 40 hp Mercedes Simplex racing car. The car’s name was apt, since Wilhelm Maybach had purposefully set about redesigning the car powered by a 29.4 kW engine to achieve more power, simpler operation and greater reliability. In this racing car, Count William Eliot Zborowski took second place in the heavy car class in the Paris–Vienna long-distance race in June 1902. The stretch from Paris to Innsbruck also served as the third event in the series of races for the legendary Gordon Bennett Trophy.
The Gordon Bennett Trophy was the most important competition series in international motor racing. The American publisher and editor of the ‘New York Herald’, James Gordon Bennett, who lived in Paris, created this race in late 1899. It was held once each year as a competition of nations. The cars had to weigh at least 400 kg, but no more than 1000 kg, and had to be manufactured down to the very last bolt in the country for which they competed. The nation that fielded the winner was allowed to organise and hold the race the next year. The Gordon Bennett races of the early 20th century originated the tradition of national colours for racing cars. DMG started for Germany in cars with a white livery. Other colours which became established during these years were green for England, red (originally black) for Italy, blue for France, black and yellow for Austro-Hungary and red and yellow for Switzerland.
The British driver Selwyn Frances Edge had won the 1902 race in a Napier, so the 1903 race should have taken place in England. But as road racing was prohibited there, the event was moved to Ireland. A series of serious accidents at the Paris–Madrid race in May 1903 prompted one city after another to ban motor racing. So it was that the start of the era of racing on oval circuits began in Ireland. DMG had intended to enter the new generation of Mercedes Simplex racing cars in the event, using the more powerful variant with 66 kW engine built specifically for competition. However, the 90 hp Mercedes racing cars fell victim to a major fire that gutted the Cannstatt factory on 10 June 1903. Instead, three 60 hp Mercedes Simplex lined up at the start in Ireland on 2 July, which DMG had bought back or loaned from private customers with racing ambitions.
The Daimlers drove to Ireland under their own power at the end of June – and went on to win. The Belgian Camille Jenatzy crossed the finish line first in the car of the American enthusiast Clarence G. Dinsmore, at an average speed of 79.2 km/h. This was the first significant international victory for DMG. As a consequence of the Daimler triumph, the next Gordon Bennett Trophy race was held in Germany in 1904. On a circuit near Homburg in the Taunus region, French driver Léon Théry came out on top. This time Camille Jenatzy in his 90 hp Mercedes racing car could manage only second, followed by Baron de Caters in another 90 hp Mercedes. Three more cars of this type started for the Austro-Daimler works in Wiener Neustadt, two of them finishing fifth and eleventh.
The 90 hp Mercedes of 1904 was almost identical with the previous year’s model, several of which were destroyed in the blaze in the DMG Cannstatt factory in June 1903. The bore was reduced from 17 to 16.5 centimetres, but the smaller displacement was offset by boosting engine speed from 950 to 1150 rpm. While Camille Jenatzy was unable to repeat his previous year’s performance in the Gordon Bennett Trophy race, Hermann Braun won the sixth Semmering race in 1904 in a new record time at an average speed of 73.2 km/h.
The racing cars for the 1905 season also built on the Maybach design of 1903 and 1904. Apart from a few minor changes to the chassis, the main modifications were to the engine. The total displacement of the four-cylinder unit was now a massive 14.1 litres, and the output of the 120 hp Mercedes Gordon Bennett racing car rose to 88 kW at 1200 rpm. However, DMG was unable to score any major successes with this car, either in the final elimination round for the Gordon Bennett Trophy in France or in the Vanderbilt Cup on Long Island near New York. This was mainly because of valve damage and time lost due to frequent tyre changes.
1906: The Grand Prix era begins
For the 1906 racing season DMG developed its first racing car with a six-cylinder engine. As early as in autumn 1905, Maybach had designed an extremely advanced unit with overhead camshaft, overhead valves and double high-tension sparkplug ignition. The engine had individual steel cylinders fitted to a light-alloy crankcase. Cooling jackets and cylinder head were designed as a common casting and welded to the steel cylinders. This basic design served Mercedes and Mercedes-Benz for several decades as a model for high-performance engines.
With cylinder dimensions of 140 x 120 millimetres and a total displacement of 11.1 litres, the six-cylinder unit developed 78 kW at 1400 rpm, or 88 kW at 1500 rpm. These engine speeds were the highest ever seen in the industry at the time. Maybach made them possible by keeping all moved masses in the valve train to a minimum. However, he did not receive the necessary support for his forward-looking engine, which was up against a conventional six-cylinder unit designed by Gottlieb Daimler’s son Paul.
DMG finally decided that for the 1906 season three vehicles would be equipped with the Maybach engine and three with the Daimler engine. However, the internal dispute resulted in a production delays, so that the Stuttgart company had to compete in the French Grand Prix near Le Mans in June 1906 with three largely unmodified 120 hp Mercedes four-cylinder engines. In this first modern Grand Prix in automotive history, Mercedes managed only tenth and eleventh places.
Hermann Braun won the Semmering race on 23 September 1906 in a 100 hp Mercedes with a four-cylinder engine. This success, where Braun again set a new record with an average speed of 77 km/h, confirmed him as the winner of the first Semmering Challenge Cup.
After a generally rather disappointing season in 1906, DMG was determined to be better prepared for the 1907 racing calendar. The new 120 hp Mercedes Grand Prix car was based in many ways on the 1905 model that was then used in modified form also in 1906. The frame side member with offset over the front axle and flatter-mounted front leaf springs came from Maybach’s six-cylinder racing car. For the first time DMG also used friction dampers. But the engine was again designed as a four-cylinder with a total displacement of 14.4 litres comprising two pairs of cylinders from Paul Daimler’s six-cylinder unit. At the French Grand Prix at Dieppe on 2 July 1907 the only Mercedes to reach the finish line was the car driven by Victor Hémery, coming in no better than tenth.
Mercedes enjoyed more success with its participation in races at the new Brooklands circuit in England. In the inaugural race on 6 July 1907, J. E. Hutton in a 120 hp Mercedes won the Montague Cup and prize money of 1400 pounds Sterling, followed by Dario Resta in a car of the same model. Mercedes cars won many more races in the first Brooklands season. On 5 August, J. E. Hutton won the Heath Stakes, while on the same day Dario Resta emerged as winner in the Prix de la France race held on the British circuit, with Hutton coming in second.
1908: Victory in the French Grand Prix
On its third attempt, DMG finally succeeded in winning the French Grand Prix, the most prestigious motor race of the day. On 7 July 1908, Christian Lautenschlager drove the new 140 hp Mercedes Grand Prix racing car to victory ahead of two Benz cars. The event was raced over ten laps of a 77-kilometre oval circuit on public roads near Dieppe, for a total distance of 769.88 kilometres. 48 cars took part, nine of them from Germany: three Benz, three Mercedes and three Opel vehicles. France naturally wanted to underscore its role as the ‘grande nation’ of motor sport in this race against the spectacular backdrop created by some 300,000 spectators, but this hope was dashed by the triple victory of the German racing cars.
The course with its many potholes made the Grand Prix a tough ordeal for both the drivers and their cars. Some teams dropped out simply because they had not stocked enough replacements for the many tyres falling victim to the poor roads. The tyres of the Mercedes cars also took a beating, with Christian Lautenschlager (the eventual winner) making 22 tyre changes in his 140 hp Mercedes Grand Prix car during the race. Despite the adverse conditions, Lautenschlager crossed the finish line in first place after 6 hours, 55 minutes and 43 seconds, almost nine minutes ahead of Hémery and Hanriot, both in Benz cars. His average speed over the entire distance was an impressive 111.1 km/h. Team-mate Otto Salzer turned in the fastest lap, in a time of 36 minutes and 31 seconds, equivalent to an average speed of 126.5 km/h.
Issue No. 29 of 1908 of the Allgemeine Automobil-Zeitung reviewed the day’s events as follows: ‘Lautenschlager was greeted by a band playing the German national anthem. The spectators in the stands applauded; the driver was not in the least fatigued. It was wonderful to see how the Mercedes sped around the course. Pöge drove a very bold race, overcoming his fatigue; Hémery and Hanriot likewise had good chances of winning. Erle was not very familiar with the course, and put in an extraordinarily good performance.’
The car’s engine had twin camshafts in the cylinder block, overhead intake valves and side exhaust valves. The in-line four-cylinder was thus built according to Wilhelm Maybach’s design concept for the four-cylinder racing engines of the years from 1903 to 1906. From a displacement of 12.8 litres the engine developed an output of 99 kW at 1400 rpm. The winning car at Dieppe was also the basis of the 1908 Mercedes 150 hp Semmering racing car in which Otto Salzer won the tenth Semmering race on 20 September 1908, entered for the first time in the open racing car class. Salzer set a new record in the process, with an average speed of 81.2 km/h. One year later he raised the bar still further with a speed of 84.3 km/h. In 1910, the engine was fitted with aluminium pistons, attaining an output of 132 kW. The vehicle fitted with this engine ended its career on a fantastic note on 16 July 1910, reaching a top speed of 173.1 km/h over the flying kilometre during Ostende Week (Belgium).
The first French Grand Prix marked the birth of modern formula racing. But it took some time for a regular series to develop out of this one-off event: because of the high entry fees, the leading car brands boycotted the Grand Prix planned for 1909 so that it had to be cancelled. The next French Grand Prix was not staged until 1912. During this period DMG did not enter any factory teams in race events, but continued to build top-flight racing cars for private enthusiasts.
The 37/90 hp racing car introduced in 1911 was a high-performance vehicle aimed precisely at this group. Its 9.5-litre four-cylinder engine had a combined battery and magneto ignition with two spark plugs per cylinder. A notable design feature was the three-valve technology used for the first time in a Mercedes: one intake valve and two exhaust valves per cylinder, driven in the conventional manner from a camshaft in the cylinder block, via pushrods and rocker arms. An uprated version of this production engine was used in several racing cars. From 1911 to 1913, two of these cars, with Spencer Wishart and Ralph de Palma at the wheel, scored numerous racing successes in the USA. Both had wooden spoke wheels and were fitted with a V-shaped radiator cowling.
In 1913, DMG planned to return to Grand Prix racing and built two entirely new racing cars: the 90 hp Mercedes and 100 hp Mercedes racing cars, both fitted with engines originally designed as aircraft powerplants. These engines were awarded second and fourth places in the Emperor’s Prize competition for the best German aircraft engine in January 1913. Featuring an overhead camshaft and overhead valves, they had many points in common with Maybach’s trail-blazing six-cylinder racing engine of 1906. The 7.2-litre DF 80 six-cylinder that took second place in the Emperor’s Prize had individual turned steel cylinders, fitted in pairs with welded-on sheet steel cooling jackets. It had an output of 67 kW at 1400 rpm. The G 4F large-displacement four-cylinder G 4F awarded fourth place in the Emperor’s Prize competition developed an astonishing 74 kW at 1350 rpm from its 9.2 litres of cubic capacity. However, the cars were unable to start in the French Grand Prix held on 12 July 1913 on the Circuit de Picardie track near Amiens: since they had not been entered by the factory itself, but by the Belgian agent Theodor Pilette, the Automobile Club de France rejected the entry.
Three of the new cars did however see action three weeks later in the Grand Prix de la Sarthe, near Le Mans: Pilette in his 74 kW four-cylinder car was in second place for much of the distance and finished third after suffering tyre problems – still an excellent performance. His team-mates Otto Salzer and Christian Lautenschlager came in fourth and sixth in their 67 kW six-cylinder cars. With their frame side members slightly tapering to a V at the front and pointed radiators, the three cars were hard to tell apart. However, on its left side the four-cylinder car had four exhaust pipes running to the manifold, whereas the six-cylinder cars had three exposed exhaust pipes. In the same race the Belgian Léon Elskamp, driving an older 37/90 hp Mercedes based on the 1908 Grand Prix car, took seventh place. Elskamp won the 1913 Grand Prix of the Belgian Automobile Club in Spa in a 16/45 hp Mercedes-Knight with an average speed of 99.7 km/h.
1914: Triumph in the French Grand Prix
Mercedes finally surpassed its success in the 1908 French Grand Prix when Christian Lautenschlager, Louis Wagner and Otto Salzer scored a triple win in 1914, once again at the French Grand Prix, raced on a 37.6-kilometre oval circuit south of Lyon. For the first time race regulations limited displacement to 4.5 litres. Daimler entered its 115 hp Mercedes Grand Prix racing car. This vehicle had a four-cylinder engine, a completely new design with overhead camshaft plus two exhaust valves and two intake valves per cylinder, marking the first use of four-valve technology in a Mercedes engine. The engineers designed the racing engine for a continuous engine speed of 3500 rpm, a sensational figure for those days. A new feature compared with the previous Grand Prix cars was the switch from chain drive to propeller shaft drive.
On 4 July 1914, after intensive preparations, the Mercedes team took the start at the French Grand Prix in Lyon with five of these cars against supposedly superior competition – principally from Peugeot and Delage from France, Sunbeam from England and Fiat from Italy. The race was over 20 laps, about 750 kilometres, on a highly testing course. Theodor Pilette and Max Sailer were forced to pull out because of technical problems, but in the remaining cars Christian Lautenschlager, Louis Wagner and Otto Salzer gained a triumphant triple victory after more than seven hours of racing, backing up, and indeed exceeding, the Mercedes success of 1908.
The engine, referred to in-house as the M 93654, was regarded as a landmark design achievement. It even served as the model for Rolls-Royce aircraft engines in the First World War. After the victory in Lyon, a vehicle was sent to England for demonstration purposes, but the beginning of the war caught people unawares and the car remained in England. Engineer Walter Owen Bentley was well aware of the car’s significance, and had it dismantled and analysed at Rolls-Royce. Bentley duly adopted the design of the valve train for his own engines.
While the war put an end to further racing activities in Europe, at least one of the 1914 Grand Prix cars continued to compete in the USA: Ralph de Palma bought one of the winning cars and scored numerous victories with it in the USA from 1914 to 1916. His most spectacular exploit was winning the Indianapolis 500 on 31 May 1915. After the war the 4.5-litre car again saw action in Europe in several races. One particularly successful driver was Count Giulio Masetti, who won a number of races in Italy in 1921 and 1922, including the Targa Florio in April 1922.
1921: A new beginning after the First World War
After the cessation of hostilities in 1918, Mercedes returned to racing activities, but in the face of extremely difficult economic and political conditions. It was only the restrictions placed on German and Austrian drivers participating in important competitions such as the French Grand Prix that forced an apparent break in the company’s racing involvement. And so the first post-war competition vehicle presented by Daimler-Motoren-Gesellschaft was the 28/95 hp Mercedes racing tourer of 1921. This model was not an entirely new development, but based on the 28/95 hp Mercedes sports tourer of 1914. It was fitted with a new engine featuring cylinders cast in pairs. The Mercedes drivers achieved some preliminary successes in this car in 1921.
In the Zbraslav–Jiloviste hillclimb, near Prague, on 25 May 1921, in a two-seater sports car with shortened wheelbase, Otto Salzer posted the best time for all classes and set a new course record. Long-distance endurance was the top priority at the Targa Florio in Sicily, where on 29 May factory driver Max Sailer came second in the overall rankings and won the Coppa Florio, as the prize for the fastest production car. Sailer had converted his racing car himself and drove it to Sicily under its own power. A year later he was back in Sicily with the 28/95 hp Mercedes. The engine now featured a supercharger, boosting output to 103 kW. Sailer was the winner in the over 4.5 litre production car category and finished sixth overall.
1922: Dawn of the supercharger era
Two 1.5 litre 6/40/65 hp Mercedes racing cars, with a completely new design featuring supercharged engines, lined at up the start for DMG in the 1922 Targa Florio. The Sicilian race was therefore the first outing for supercharged cars from Stuttgart. However, the overall winner of the 1922 Targa Florio was not a mechanically supercharged vehicle, but the 1914 Mercedes racing car driven by Count Giulio Masetti – the same vehicle Ralph de Palma had taken to the United States in 1914.
While DMG was no longer allowed to build aircraft engines after the war, the experience gained in the mechanical supercharging of aircraft powerplants was how put to good use in its automotive engines.
At the end of 1921 DMG saw a good opportunity to participate in the voiturette class of racing cars, limited to a displacement of 1500 cubic centimetres. The appeal of this class was based on its wide acceptance in England and Italy, which were seen as potential export markets, with the ability to influence trends all over the world. The M 68084 engine of the 6/25 hp supercharged car introduced in Berlin gave Daimler a good starting point, even though its displacement of 1.6 litres exceeded the limit set by the racing regulations.
The design of this basic engine was thoroughly revised for racing use, to the extent that it became the standard for all Mercedes and Mercedes-Benz racing engines into the 1950s. The bore-stroke ratio was changed to 65 x 113 millimetres to give a displacement of exactly 1499.87 cubic centimetres, utilising the 1.5-litre limit prescribed by the rules to the last tenth of a cubic centimetre. Untertürkheim also explored new avenues in cylinder head design, by creating a thoroughbred racing engine with two overhead camshafts and four acutely angled overhead valves. The spark plug was optimally located in the centre of the combustion chamber between the two pairs of valves. As in the basic engine, the camshafts were driven by a vertical shaft, but in the form of a transverse shaft arrangement for both camshafts. The high-tension magneto and the water pump were driven by transverse shafts farther down in the engine. The vertical shaft was placed at the end of the crankshaft, and the vertically positioned Roots blower was operated with a ratio of 1:1.9. Compared with the 1.6-litre engine, the supercharger was significantly larger and was engaged and disengaged by a cone clutch actuated by pressing the accelerator flat to the floor, similar to the kickdown effect in future automatic transmissions.
The output of the racing engine was given as 29 kW, and 48 kW with supercharger activated. However, measurements taken in 1948 showed an output of almost 59 kW when supercharged. In naturally-aspirated mode the engine was roughly on a par with competitors such as the Fiat 403, which however responded significantly more sensitively to accelerator positions than the supercharger with its sudden bursts of power – much like the early specimens of the turbocharged engines of later years. 24 units of the Mercedes-Benz high-performance engine were built at the time, 3 of them for use in power boats and 21 in road vehicles. Brakes were adapted to cope with the high power output, including the use of four-wheel brakes in the Targa Florio cars.
The 1.5-litre racing car was first used in racing in April 1922, with two of them entered in the Targa Florio in Sicily alongside two 1914 Mercedes Grand Prix racing cars and two 28/95 hp racing tourers, one of which also was fitted with a supercharger. Paul Scheef could only manage an overall 20th place finish with one of the two 1.5-litre supercharged cars, while Italian driver Fernando Minoia in the second supercharged car was forced to retire from the race. Despite this somewhat inauspicious start, the 6/40/65 hp Mercedes founded a whole line of supercharged racing cars which in the years from 1924 achieved remarkable successes for the Mercedes and Mercedes-Benz brands and gained worldwide fame.
The near-series 6/25/40 hp sports tourer was used in numerous events with great success as from 1923. It was in this vehicle that Rudolf Caracciola enjoyed his first successes for Mercedes, for example when he won the ADAC Reich Rally from 19 to 21 July 1923 in the class of touring cars up to 6 fiscal horsepower (the „fiscal“-horsepower is calculated by a definite tax formula, which hp tax have to be paid for, being significantly under the real effective horsepower). The Mercedes 2-litre Indianapolis racing car, also developed in 1923 on the basis of the 10/40/65 racing sports car, was the last car designed for DMG by Paul Daimler. This vehicle, which with supercharger developed 110 kW at 4800 rpm, featured the use of a roller bearing-mounted crankshaft and oil cooler for the first time. In the 1923 Indianapolis 500, Sailer and Werner drove the car to eighth and eleventh places.
When Paul Daimler left DMG, Ferdinand Porsche – previously employed at Austro-Daimler in Vienna – was appointed as the new chief designer in 1923. He developed the racing car for the Targa Florio in April 1924 based on the Indy vehicle. Numerous detailed improvements made the racer a very promising contender for victory. The race was organised at colossal expense and effort: as early as January, Stuttgart sent two test cars to Sicily, painting what proved to be winning car red instead of the usual white, for a very specific reason. This was not a friendly gesture to the host country, but shrewd tactics: since spectators were able to recognise the racing cars of other nations by their colour at a distance, some of them hurled rocks at unpopular rivals.
The 540-kilometre race ended in a victory for Christian Werner. Christian Lautenschlager finished in tenth place, and a new driver on the DMG team – the 33-year-old Alfred Neubauer – finished 15th. Neubauer had followed Ferdinand Porsche from Vienna to Untertürkheim on Porsche’s appointment as chief engineer, and he went on to write racing history for Mercedes-Benz – not as a driver, but in the role of racing manager. After the Targa Florio the car was used in a number of other races. For sprints and hillclimb events, Otto Salzer even had the 4.5-litre engine from the 1914 Grand Prix car installed in the chassis, additionally fitting it with a supercharger. In this ‘grandmother’, as he dubbed the monster, he won the Semmering race in September 1924. Rudolf Caracciola and Alfred Rosenberger also subsequently competed in this vehicle.
Less successful than the Targa Florio car was the eight-cylinder ‘Monza’ racing car designed by Porsche, also introduced in 1924. This first DMG car with an eight-cylinder engine was also the first independent design created by Ferdinand Porsche in his new role as chief design engineer of Daimler-Motoren-Gesellschaft. Two of these 2-litre Grand Prix racers duly lined up at the start of the Italian Grand Prix at Monza in October 1924, painted white, with their ferocious-looking radiators and bonnets. But the 125 kW car with its new supercharged eight-cylinder powerplant proved very hard to control and highly problematic. Count Zborowski, one of the drivers alongside Masetti, Neubauer and Sailer, lost his life in an accident during the race. The greatest victory of the Monza car was to come later, in the 1926 German Grand Prix on the Avus with Caracciola at the wheel.
Another highly spectacular automotive creation, dating from 1924, was developed from an idea by Christian Werner and Alfred Neubauer. Although rather rustic in appearance, the racing car transporter, based on a 24/100/140 hp Mercedes, was nonetheless ideal for the speedy and safe transportation of the team’s racing cars. Before this they sometimes had to travel to the race venue under their own power. Mercedes-Benz returned to the idea of a fast transporter vehicle in 1955, enhancing the concept in the form of the elegant Silver Arrow transporter.
The last great racing car presented by DMG before the merger with Benz & Cie. was a model from 1925. The 24/100/140 hp Mercedes Model K Racing Touring Car, to give the six-cylinder vehicle its full name, was planned as a heavy sports touring car. ‘But it was a racing car design that Porsche served up,’ wrote Karl Eric Ludvigsen, speaking of the ‘K’. Developing up to 118 kW with supercharger activated and with a top speed of 124 km/h, the new car founded the legendary family of heavy supercharged cars from Mercedes-Benz: the S, SS, SSK and SSKL models that were to dominate the racing scene for many years beginning in 1926.