The Mercedes-Benz 300 SLR (W196S) was a 2-seat sports racer that took part in the 1955 World Sportscar Championship before a catastrophic crash and fire at Le Mans later that year ended its domination prematurely.
Designated "SL-R" (for Sport Leicht-Rennen, eng: Sport Light-Racing, later condensed to "SLR"), the 3-litre engine was derived from the company's Mercedes-Benz W196 Formula One racer. It shared most of its drivetrain and chassis with the 196's fuel-injected 2,496.87 cc straight 8 bored and stroked to 2,981.70 cc and boosted to 310 bhp (230 kW).
The W196s monoposto
driving position was modified to standard two-abreast seating,
headlights were added, and a few other changes made to adapt a strictly
track competitor to a 24-hour road/track sports racer.
Two of the nine 300 SLR rolling chassis produced were converted into 300 SLR/300 SL
hybrids. Effectively road legal racers, they had coupé styling,
gull-wing doors, and a footprint midway between the two models.
When Mercedes cancelled its racing programme after the Le Mans disaster, the hybrid project was shelved. Company design chief Rudolf Uhlenhaut, architect of both the 300 SLR racer and the hybrids, appropriated one of the leftover mules as his personal driver. Capable of approaching 290 km/h (180 mph), the Uhlenhaut Coupé was far and away the fastest road car in the world in its day.