The Porsche 550 followed the precedent set by the 1948 Porsche 356/1 prototype designed by Ferry Porsche, which was also mid-engined, as well as Spyder prototypes built and raced by Walter Glöckler from 1951. The car was formally introduced at the 1953 Paris Auto Show.
Power came from the Porsche Type 547 engine, developed by Dr. Ernst Fuhrmann and often called the "Fuhrmann Engine." It was an all-aluminium naturally aspirated air-cooled four-cylinder boxer unit with double overhead camshafts per bank driven by vertical shafts, actuating two valves per cylinder. With a bore and stroke of 85 mm by 66 mm, displacement was 1.5 litres (1,498 cc). In initial form it produced 110 PS (81 kW) at 6,200 rpm. The engine was mounted in front of the rear axle in a rear mid-engine, rear-wheel-drive configuration, giving balanced weight distribution and largely neutral handling, though the low rotational inertia about the vertical axis could produce sudden rotation that demanded driver respect.
The first 550 used a fully synchronised four-speed gearbox; from 1956 a five-speed unit was fitted. A limited-slip differential prevented excessive wheelspin through corners. The 1956 550A variant introduced a lighter and more rigid spaceframe chassis over the original design.
The 550 won its first race on its competition debut — the Nürburgring Eifel Race in May 1953. Later that year it took class wins at the 24 Hours of Le Mans and the Carrera Panamericana. The Carrera Panamericana victory was commemorated in the Carrera branding subsequently applied to high-performance Porsche models.
The silver factory (Werks) cars were identified at the pits by painted spears of different colours on the rear fenders. Hans Herrmann's red-tailed car No. 41 was particularly successful and became one of the most photographed Porsches of the era. During the 1954 Mille Miglia, Herrmann famously drove the low-slung 550 under closed railroad crossing gates — an image that became one of the iconic photographs of 1950s road racing.
For such a limited production run of 90 cars, the 550 was remarkably consistent: it was rarely absent from the top three positions in its class. At the 1954 24 Hours of Le Mans, only a 1.5-litre OSCA MT4 finished ahead, and that car was subsequently disqualified. In the 1957 race, a 1.1-litre Lotus Eleven trailed the 1.5-litre winning 550 by one lap.
The 550A gave Porsche its first outright win in a major sports car event at the 1956 Targa Florio, though this race was not part of the World Championship that year. During this period Porsche also became the first European car manufacturer to secure race sponsorship for North American events, working through Fletcher Aviation — a company Porsche collaborated with on a light aircraft engine — along with later sponsors Telefunken and Castrol.
Privateers continued racing the 550 after the works team moved to the 718 RSK in 1957. The car was effectively road-legal, and it was common for private owners to drive it to the circuit, race it, and drive home. One car was purchased by Yugoslav leader Josip Broz Tito for racing driver Milivoje Bozic, who finished third in the 1000 km Supercortemaggiore Grand Prix at Monza in 1958 using a single set of tyres, before winning his class in the 1960 European Hill Climb Championship; this car was sold to Prada in 1961.
Perhaps the most widely known Porsche 550 is chassis 550-0055, purchased by actor James Dean on 21 September 1955, shortly before the end of filming on Giant. Dean traded in his 356 Porsche Super Speedster at Competition Motors and immediately entered the Salinas Road Race. On 30 September 1955, Dean was fatally injured when the car was involved in a collision at the intersection of California Routes 46 and 41 near Cholame. The connection between the 550 Spyder and James Dean made it one of the most culturally significant automobiles of the twentieth century, and also one of the most frequently replicated.
The 550's successor, the Porsche 718 (RSK), was even more successful. The Spyder lineage continued through the RS 60 and RS 61 models into the early 1960s. The Porsche Boxster 550 Spyder — introduced as a modern tribute — and the RS Spyder Le Mans Prototype effectively revived the Spyder name for later generations. The mid-engine layout pioneered by the 550 became the standard configuration for top-level single-seater and sports car racing by the mid-1960s, making it one of the most conceptually influential racing cars of its era.