But starting with the GP car’s 2.5 liters meant that the 300 SLR—as it was known—could have no more than 3.0 liters. Mercedes racing chief Alfred Neubauer considered this inadequate against the 3.7-liter Jaguar D-Types, Ferraris of up to 4.9 liters and 5.4-liter Cunninghams. The man in charge of the car’s design, Rudolf Uhlenhaut, felt it would be able to do the job, as had indeed the racing 300 SL of 1952, winner at Le Mans and Mexico.

As far as one man was concerned, Daimler-Benz engineering chief Fritz Nallinger, the 300 SLR was arriving a year in arrears. When he approved the program for new eight-cylinder racing cars, he demanded assurance that the first sports cars would compete in the 1954 Mille Miglia. Alfred Neubauer had the tricky task of convincing Nallinger that the Grand Prix car had to have priority, if only to allow him to overcome Juan Fangio’s desire to stay with Maserati instead of jumping ship to the unproven and elaborate German cars.

Thus on May 1, 1955, the 300 SLR was a year late in making its debut in the Mille Miglia, scoring a record-breaking one-two finish with the respective drivers, Stirling Moss and Fangio. But the lengthy final testing and circuit-learning the 992-mile course before the race meant that Mercedes abandoned its entries in the 1000 kilometers of Buenos Aires on January 23 and the 12 Hours of Sebring on March 13.

Its Mille Miglia success and a deadly crash and withdrawal at Le Mans in June found Mercedes‑Benz trailing in the Sports-car Championship with only 8 points against 16 for Jaguar and 18 for Ferrari. After the cancellation of that year’s Carrera Panamericana only two races remained in the 1955 Championship season, the Tourist Trophy at Dundrod, Northern Ireland, and in Sicily’s Targa Florio. Both were demanding venues unknown to the modern Mercedes racing team.

With only two races to go it seemed quixotic to entertain the idea of catching up, but the results of the Tourist Trophy gave Alfred Neubauer new hope. By finishing one‑two‑three at Dundrod Daimler‑Benz shut the others out of the higher positions and brought its total to 16 points, trailing Ferrari’s 19. To win the championship, Neubauer calculated, his cars would have to win the Targa Florio and keep Ferrari from finishing better than third. If a Ferrari were to place second, the two rivals would tie for the championship.

A try for victory in the Targa would be a tremendous gamble for Daimler‑Benz against heavy odds, for the Sicilian race was traditionally dominated by Italian cars and drivers. The last three races had been won by Italians driving Lancias. But Untertürkheim had its own Targa Florio tradition from its victories in 1922 and 1924, races in which a slimmer “Don Alfredo” had been a driver, not a team manager.

Returning from Northern Ireland, Neubauer went directly to Frankfurt where many Daimler-Benz executives gathered for the opening of the biennial automobile show. There he learned that on that very morning the management committee had decided to pass up the Targa in favor of a non-championship sports-car race in Venezuela, an important export market for Mercedes‑Benz cars.

Collecting Uhlenhaut as an ally, Neubauer sought to convince Fritz Nallinger—a man of Benz rather than Daimler background—that the cars should go to Sicily and that they could win there. Nallinger’s assent was the key to getting the approval of managing director Fritz Könecke for an assault on the Targa—which was less than three weeks away. On September 24 Neubauer’s office asked Artur Keser, the company’s press chief, to inform Nallinger that Könecke approved the Targa Florio participation.

Neubauer gained in intensity what he lacked in time for preparations for his return to Sicily. Already in Palermo on October 2, Neubauer informed all the participants about the organizational details. The next day this was supplemented with a detailed personnel schedule and hotel arrangements by Alexander von Korff, Neubauer’s assistant.

A flurry of telegrams rounded up Neubauer’s drivers from all over the world. “Practice and reconnaissance were interrupted by a nasty bout of flu,” said Stirling Moss, whom Neubauer’s office found holidaying on the French Riviera. “Nevertheless I spent long hours trying to learn the mountain circuit in the Mercedes saloons and a 300 SL. I recommended Peter Collins as a very capable and quick co-driver. We were to share my usual car, the Mille Miglia and TT winner chassis 0004.”

Like Collins, Desmond Titterington was a newcomer to Mercedes ranks. Born in County Down, Northern Ireland, he had excelled there in the just-raced Tourist Trophy. He had shared the wheel of a Jaguar D-Type with Mike Hawthorn, the duo leading the race until the last lap when engine trouble dropped them to fourth behind the three Mercedes entries. Deeply impressing Neubauer, Titterington’s display on a challenging road course brought the reward of a seat in 300 SLR chassis 0003 in Sicily, shared with American star John Fitch after Hans Herrmann had declared himself unready to compete. SLR 0005 was piloted by Juan Fangio and his chosen co-driver Karl Kling.

The Mercedes-Benz team arrived in Palermo with eight sports cars including one of the 300 SLR coupes, 15 private cars, eight trucks and 45 mechanics. Some of these constituted a crew of body experts who worked night and day during practice to straighten out the cars that were being whacked against the rocks and earth of the Italian island during sessions that took place while ordinary traffic was sharing the narrow roads.

Neubauer’s October 6 telegram informed Nallinger, Scherenberg, Uhlenhaut and others that test engineer Mischke had arrived safely in Sicily. Titterington had suffered an accident with the 300 SLR, though with repairable body and rear-suspension damage. Detachment of a headlamp lens on the 300 SLR coupe was noted. Addition to the fleet of a 190 SL with a five-speed transmission from a 220 a was reported.

Neubauer’s daily report to Uhlenhaut of October 7 assessed the performance of drivers Fangio, Moss, Herrmann, and Kling as “good,” while Collins “is getting good.” In answer to Uhlenhaut’s criticism that Titterington “had too little racing experience,” Neubauer referred to his outstanding performance in the Tourist Trophy. Neubauer came to the defense of his drivers, pointing out that they completed two to four practice laps each day. He considered it important to follow a lap in the 300 SLR with one in a passenger car.

In this way 109 laps of 44.7 miles were covered in eight driving days. A total of 16,695 practice kilometers were covered on the Piccolo Madonie circuit, 15,843 accounted for by the drivers and the rest by engineers Kostelezky and Mischke. Leader was Fangio with 1,596 miles, followed by Titterington’ s 1,552, Kling’s 1,521 and 1,462 for Moss. Latecomer to the lineup John Fitch covered 1,163 training miles.

On October 10, the Monday of the week before the race, Neubauer reported the arrival of three trucks and his assistant von Korff. In heavy rain Fangio had a minor accident with the 300 SL, damaging a headlamp. This resulted in postponement of a planned night-time practice session in less traffic until damage to the 300 SL and Kling’s 220 a was repaired. On October 12 the cars for the race all covered a lap without problems and completed their night-time practice. On October 13, the Thursday before the Sunday race, they covered their second and last practice lap.

Keeping track of all these cars and drivers plus their rivals was an innovation that was intended for Le Mans but not permitted by the organizers. This was radio-relay communication between the pits and an outpost in the mountains where refreshed notice boards could be displayed to the drivers. This was of great value for the Targa Florio, where the provision of information from the pits at Cerda meant that drivers could only be updated every very-long lap. Moreover the cars were released at 30-second intervals, which made it even more difficult for team managers to monitor and report what was happening.

Their equipment consisted of Siemens Funk 516Y 333 two-way radio units installed in two passenger cars—a 170 S-V and a 180. After numerous trials the intrepid test technicians found a good location for their outpost at the edge of a quarry near Caltavuturo at an altitude of 2,100 feet, about 18 miles after the start/finish. Their information boards told drivers about the current race standing. “With two-way short-wave radio,” said engineer Heinz Lamm, “it was possible to inform the drivers about their position in the race and their last lap time very rapidly. The pits were quickly advised of any developments.”

Starting sequences were determined by a ballot in the office of the organizers. With the race rules limiting each driver’s session to five laps, a roster was laid down for the 13-lap race. Mercedes-Benz absolutely wanted to prevent two cars standing in the pits for servicing at the same time:

Team Moss/Collins, starting number 104

1st cycle Moss: 4 laps; Collins: 4 laps

2nd cycle Moss: 5 laps

Team Titterington/Fitch, starting number 106

1st cycle Titterington: 5 laps; Fitch: 3 laps

2nd cycle Titterington: 5 laps

Team Fangio/Kling, starting number 112

1st cycle Fangio: 5 laps; Kling: 3 laps

2nd cycle Fangio: 5 laps

Though steady rain for almost a week before the race brought torrents carrying mud and rubble that flooded sections of the route, the sun shone obligingly on the day of the Targa. “I hardly slept at all the night before the race,” Moss recalled, “and felt pretty awful when I arrived at the start between the sea and the small town of Cerda. I perked up once seated in the car and felt better still when I found myself in the lead! Eugenio Castellotti, Ferrari’s great hope, lay second, with Fangio on his tail third. I accumulated a minute’s lead on my opening lap and after three laps my cushion was five minutes.

“Far up in the mountains,” Stirling added, “I was just leaving a right-hand curve and had the car set up nicely through a fast left-hander when I lost control on either mud or loose gravel. The SLR bounced off a bank and hurtled straight off the edge of the road into space. I was quite frightened at this point because I hadn’t a clue whether we were flying over a drop of three feet or three hundred! Fortunately the roadside field sloped downhill just there. When I crunched down to earth I had fallen only ten or twelve feet. The problem then was to find a way back on to the road because the car, although battered, was still running.

“Some locals rushed to my assistance,” Moss recalled, “and after a lot of maneuvering and pushing and yelling I managed to gun the car back onto the road and tear off towards the pits. I had lost about twelve minutes and now lay a distant fourth. Back at the pits, Neubauer, Peter and the crew had virtually given me up for lost until I came hurtling in. They checked the car quickly and Peter took off with the bit firmly between his teeth.” His 300 SLR’s frame was bent and its engine had needed almost three gallons of water.

That was their scheduled stop after four laps, in the third of which Stirling set a new record of 43:07 with an average speed of 62.25 mph. Castellotti and Fangio, his closest challengers, were the first of three rivals ahead of Peter Collins. After the pit stop of 3:23 minutes Collins, who had never previously raced a Mercedes-Benz, took the wheel of the 300 SLR lying in fourth place. At once he started lapping at blistering speed, eventually having his own run-in with a wall. “It wasn’t a very good wall,” he told Moss. “It simply seemed to crumble away before me.” Four laps later, when Peter handed the car back, the Mercedes newcomer had regained the lead.

“The car sounded okay,” said Moss, “and Peter was going like a bomb. He had done the standing lap in 44:22—considerably quicker than the other cars’ flying laps at the time.” On his second round, with a time of 43:28 Collins set the race’s third-fastest lap. Karl Kling and John Fitch had held up their ends during their middle stints. But when after lap 8 Kling handed over to Fangio, the filler cap refused to budge. Opening it by force stretched refueling to 2:22, which dropped Fangio to third. He was no longer keeping a Ferrari out of second place and denying the Scuderia the Championship.

On every subsequent lap the Argentinian was considerably faster than the Ferrari. inexorably reducing the gap. After the ninth lap Fangio had a two-minute deficit to Castellotti’s relief, Frenchman Robert Manzon. The latter obliged by striking a rock during his 11th lap, losing five and a half minutes with a wheel change. Juan Fangio defended his second place to the finish, together with his partner Kling assuring Mercedes-Benz of the 1955 World Sports-car Championship for Mercedes-Benz.

The winning Moss-Collins team set a new Targa Florio record with an average speed of 59.83 mph. A figure that speaks for the race’s challenge, it was a healthy seven percent faster than the previous record. “Despite Stirling’s efforts and my own to write the machine off,” Collins said afterward, “by going over precipices and through walls and shunting other cars, still somehow the car managed to last right through this race.”

The Titterington-Fitch duo were fourth, some 10 minutes behind the winners after almost ten hours of the most demanding racing on the planet. “The durability of the SLR was unbelievable,” Fitch reflected. “As demonstrated at the Targa, it would stand up to incredible abuse and continue to operate perfectly. This highly-developed sports-racing machine was built like a tank yet was as responsive as a jungle cat—a fabulous accomplishment in the field of automotive design.”

“That was the last time I ever drove a Mercedes-Benz racing car in anger,” reflected Stirling Moss, “which I was sad about. But for me the 300 SLR obviously has very special significance as the one car in which I could with some confidence believe that I could give Fangio a race!”

Some of the special features of the Targa cars, such as drop‑down armored covers over the headlamps, weren’t essential for that race but were being tested for the future. Although it was already known that the Stuttgart team would leave Formula One in 1956, on September 28 Fritz Nallinger had confirmed to Neubauer that the sports cars would compete in eight to ten events in 1956 He asked the team manager to let him have a list of suitable races for his review when he returned from Sicily. From his command post in a villa near Palermo, Neubauer dictated a reply on October 9, giving Nallinger his thoughts on the 1956 competition calendar.

Despite these assurances, and despite the storybook victory in the Targa Florio and the winning of the Sports-car Championship, rumors were flying among the mechanics about the future of the racing effort as they drove north again to Stuttgart. These were confirmed on October 22 when the traditional end‑of‑season press conference became the platform for the announcement that Daimler‑Benz was withdrawing its sports cars, as well as its racing cars, from further competition.

Alfred Neubauer learned of the decision in Sicily when he returned to his villa to find a letter from Fritz Nallinger awaiting him. It was dated September 12. It read in part as follows: “After mature deliberation the management committee has decided…to absent itself…irrevocably from motor racing for several years.” And so it did, for years that became decades.