Nicknamed "Superswede",[a] Peterson twice finished runner-up in the Formula One World Drivers' Championship in 1971 and 1978, and won 10 Grands Prix across nine seasons.

In his three-year spell with the team, he took six podiums, most of which were scored during the 1971 Formula One season in which he also finished as runner-up in the Drivers' Championship.

After seeing out his three-year contract at March, Peterson joined Colin Chapman's Team Lotus in the 1973 season, partnering defending champion Emerson Fittipaldi.

After a poor 1975 season, Peterson moved back to March and scored his final victory for the team at the 1976 Italian Grand Prix.

Even after his elevation to F1 status Peterson still drove in lower echelon racing series (which was common at the time), winning the 1971 European Formula Two Championship driving for March.

The limited budget of Crabbe's privateer team allowed only minimal testing, and Peterson qualified 12th out of 16 cars in the race.

He was 10 places behind Jackie Stewart and Chris Amon, both on the front row of the grid in their newer specification 701s, but only just behind the more experienced Jo Siffert in the second works March.

Five Formula One Grand Prix second places earned him the position of runner-up to Jackie Stewart in that year's World Championship.

Within that year, Peterson drove in the World Sports Car Championship driving an Autodelta Alfa Romeo to win the Watkins Glen 6 hours.

He took three more wins that year, in Austria, Italy and the United States, but poor reliability restricted him to only third place in the World Championship at season's end.

For instance, he was paired with Hans-Joachim Stuck in a BMW 3.0 CSL for the South African "Wynn's 1000" in November 1975, where they started on pole but finished in second after a number of stops with engine vibrations, spark plug, and similar problems.

[8] Peterson retired from the opening four races of 1977, he spun off in Argentina, was involved in a crash with Jochen Mass's McLaren and Clay Regazzoni's Ensign in Brazil, and suffered fuel systems problems in South Africa and United States West.

Peterson retired from the last two races of 1977, a fuel leak in Canada and in Japan, he collided with Gilles Villeneuve's Ferrari but the crash killed a marshal and photographer as they were standing in a prohibited area of the track when the accident occurred.

[15] Peterson refused to contribute to any controversy, and on numerous occasions dismissed the speculation by stating that Andretti had simply turned the faster time.

The front four, Andretti, Gilles Villeneuve, Jean-Pierre Jabouille and Niki Lauda, were far enough ahead to avoid any drama, but Peterson had made a poor start from the third row of the grid, and was immediately passed by Alan Jones, Jacques Laffite and John Watson.

Jody Scheckter and Riccardo Patrese, starting 10th and 12th, had moved to the right across the line that separated the Grand Prix front straight from the approach to the old Monza banking.

While Scheckter's Wolf was able to rejoin the track well ahead of the bunching pack, Patrese moved back in just ahead of James Hunt, who feinted left and collided with Peterson, with Vittorio Brambilla, Carlos Reutemann, Hans-Joachim Stuck, Patrick Depailler, Didier Pironi, Derek Daly, Clay Regazzoni and Brett Lunger all involved in the ensuing melee.

[23] "It was so unfair to have a tragedy connected with probably what should have been the happiest day of my career", Andretti said, "I couldn't celebrate, but also, I knew that trophy would be with me forever.

At his funeral, the pallbearers included Åke Strandberg, James Hunt, Jody Scheckter, John Watson, Emerson Fittipaldi, Gunnar Nilsson and Niki Lauda.

Driver Riccardo Patrese and race director Gianni Restilli were both charged with roles; Patrese, for manslaughter because of an unsafe maneuver on track which was considered to be a primary cause of the wreck, and Restilli, as contributing to Peterson's death by starting the race with a premature start signal.

[35] Superswede: A film about Ronnie Peterson (2017), directed by Henrik Jansson-Schweizer, with the participation of Mario Andretti, Emerson Fittipaldi, Nina Kennedy, and Niki Lauda, is available on YouTube, as are several other short tributes.