Mercedes-Benz 300SL
Daimler-Benz and German rival Auto-Union had been almost invincible in 1930s Grand Prix racing. But the Second World War’s devastation took its toll and by the early 1950s D-B still wasn’t financially or technically ready to return to Grand Prix competition.
Daimler-Benz was the manufacturer of Mercedes-Benz cars and trucks, but it took until 1951 to introduce its all-new post-war 220 and 300 sedans. With modern passenger models in production the company felt ready to pursue some of its pre-war racing glory. As an interim step to the new Formula 1 it chose sports car racing by creating a sports racer using M-B 300 sedan parts. The 300 was not a racing car but its driveline and chassis components were robust enough for competition.
The 3.0 litre (183 cu in.) single overhead camshaft 12-valve, short-stroke, inline six had a sturdy, forged, fully counterweighted steel crankshaft that ran in seven generous main bearings. An aluminum bodied coupe with a low, aerodynamic drag (0.25 coefficient of drag) was created and designated the 300SL (for 3.0 litres, Sport and Light).
Since the sedan frame was too heavy a bridge-like “space frame” was fabricated from small diameter tubes. It was strong and light but extended halfway up the sides of the car, precluding regular doors. The designers, therefore, placed the door-bottoms at mid-level and extended the tops into the reinforced roof where they were hinged near the middle of the car and rose vertically.
Quickly dubbed gullwing doors they were the 300SL’s most striking and imitated feature. An engineering solution had turned into an iconic styling signature. The high sills made entry and exit awkward so the steering wheel tilted down to aid access.
Once inside it was snug and comfortable compared with open sports cars and had excellent all-round visibility. The 300 sedan’s 2,996 cc modestly stressed engine produced just 115 horsepower at 4,600 rpm. But it was sturdy enough to reliably develop more than double that; when the production 300SL was introduced it was rated at 240 horsepower.
Carburetors were used during development, but the production model got Bosch mechanical fuel injection, the world’s first four-stroke, gasoline-engine production car with this feature.
It also got racing-type drysump lubrication, and to clear the low hood the engine was tilted 50 degrees to the left. The 300SL quickly made its mark in competition, winning, among others, the 1952 Le Mans, France, 24-hour race and Carrera Panamericana (Mexican Road Race). It was also successful in rallying. After pointing the way to D-B’s return to Grand Prix racing, the 300SL would likely have been relegated to D-B’s museum like other M-B racers had it not been for the intervention of Max Hoffman, Mercedes-Benz’s New York-based American distributor. Hoffman was the imported car czar of the United States.
He had keen marketing sense and his Manhattan dealership sold everything from Volkswagens to Rolls-Royces. Hoffman became a Mercedes distributor in 1952, and when he saw the Mercedes-Benz 300SL sports racing car he knew it would sell in America. He implored D-B to make it a production model and backed up his conviction by ordering 1000 of them, an opportunity too good for D-B to pass up.
The production Mercedes-Benz 300SL gullwing coupe, and less potent four-cylinder 190SL convertible, made their debut at the New York Auto Show in February 1954. The 300SL was a sensation with the public and motoring press, and production began that summer.
The 300SL fulfilled its performance promise. Road & Track (4/55) reported the 1,229 kg (2,710 lb) coupe accelerated from zero to 97 km/h (60 mph) in 7.4 seconds, and to 161 (100) in a mere 17.2 seconds. It reached a top speed of 225 km/h (140 mph). R&T called it “...the ultimate as an allround sports car,” concluding that “The sports car of the future is here today.” The 300SL had a hefty price - some $8,000 - a lot of money when a new Cadillac could be had for $5,000. This, in part, is probably why only 1,400 gullwing coupes were produced from 1954 to ‘57.
It was replaced by the 300SL roadster with a frame modified to allow conventional doors, and with D-B’s low-pivot rear swing axle assembly replacing the traditional swing axles. Four-wheel disc brakes came in 1961, and the roadster remained in production until 1963; 1858 were built.
The Mercedes-Benz 300SLs left an indelible impression because it had everything. First, fuel injection was a significant engineering advance. And it had outstanding performance, impeccable racing credentials and the cachet of those gullwing doors, which M-B more recently reincarnated in its SLS model.
The 300 SL is one of history’s great automobiles, even though it was not originally intended for production. It has become a very sought after and expensive collectible.