s. The 300 SL has a steel
tubular frame chassis, with a steel body combined with an aluminum bonnet, doors, dashboard, and boot lid to further reduce weight. An additional could be eliminated with an expensive all-aluminum body, but only 29 were made. Storage space for luggage is behind the seats in the coupé; the boot only holds a spare wheel and fuel tank. The roadster was available with two custom-fitted leather suitcases for the larger boot. The coupé's windows are fixed and roll down in the roadster.
Exterior The body consists mainly of sheet steel, with the bonnet, boot lid, dashboard, sill, and door skins made of aluminum. Silver-grey was the standard color; all others were options. The objective of the overall design was to make the vehicle as streamlined as possible. The width of the tubular frame along the cockpit allowed the cabin roofline to be inset considerably on both sides, dramatically reducing the front area. The structure was also quite high between the wheels, prohibiting the attachment of standard doors. The only option – already used on the W194 race car – which would allow passengers over its high, deep sill was a
gullwing door. The car’s distinctive eyebrows are a functional feature in the front, both physically and aerodynamically deflecting road water from the windscreen, and stylistic in the rear, added for visual symmetry.
Engine The
Mercedes-Benz M198 engine is a water-cooled
overhead cam straight six. Like the racing Mercedes-Benz
M194, the 300 SL borrowed the basic two-valves-per-cylinder M186 engine from the regular four-door
300 (W186 "Adenauer") luxury
touring car introduced in 1951. The result was aerodynamic efficiency and an enormous,
sand-cast aluminum intake manifold as wide as the engine. The engine was coupled by a single-disc dry
clutch to a four-speed transmission with gear ratios of 3.34:1, 1.97:1, 1.39:1, and 1:1, and a reverse ratio of 2.73:1. From March 1963 to the end of production later that year, a light alloy engine block was installed in 209 vehicles.
Chassis Like modern racing cars, the 300 SL has a
tubular frame, designed by Mercedes head engineer
Rudolf Uhlenhaut and made of
chrome-molybdenum steel. Such a frame provided high rigidity with low mass. Thin straight tubes were assembled as triangles, with the finished frame weighing a remarkable . Elements of the coupé frame fill span the entire width of the vehicle’s track from wheel to wheel, making for an unusually high and deep threshold for access to the passenger compartment. The upper tube is so high it is level with the driver's elbow,
Suspension The 300 SL's
4-wheel independent suspension was borrowed heavily from the regular Mercedes-Benz
W186 "Adenauer" luxury tourer, given a sportier tuning. Front-to-rear weight distribution is almost exactly in the center of the vehicle. The front suspension consists of unequal-length
double wishbones,
coil springs,
hydraulic telescopic shock absorbers, and an
anti-roll bar. The rear has a low-pivot
swing axle,
radius arms, and coil springs. Being jointed only at the
differential (lacking a modern
constant velocity joint as used today with independent suspension), the swing axle could make rear end cornering treacherous at high speeds or on bad roads due to extreme changes in
camber. This was remedied in the roadster by switching to a high-pivot geometry. A
brake booster drew vacuum from the
intake manifold to assist pedal effort. Brake shoes were wide. The front drums had double cylinders, the rear single. The handbrake was mechanical, acting only on the rear wheels. In March 1961
disc brakes replaced drums all round. The wheels were riveted steel hub/aluminum rim.
Rudge 5J × 15-inch rims were a valuable option. ==Roadster==