James Hunt and Niki Lauda are exceptional racing car drivers who first develop a fierce rivalry in 1970 at a Formula Three race in London, when both their cars spin before Hunt wins the race. Hunt is a brash and self-confident individual, while Lauda is a cool and calculating technical genius who relies on practice and precision. Lauda takes a large bank loan from Austria’s Raiffeisen Bank (wearing their logo thereafter) to buy his way into the BRM Formula One team, meeting teammate Clay Regazzoni for the first time. Meanwhile, Hesketh Racing, the fledgling racing team Hunt drives for, enters Formula One. Lauda then joins Scuderia Ferrari with Regazzoni and wins his first championship in 1975. Hesketh closes down after failing to secure a sponsor, but Hunt joins the McLaren team. During this time, Hunt marries supermodel Suzy Miller, while Lauda develops a relationship with German socialite Marlene Knaus.
The 1976 season starts with Lauda dominating the first two races while Hunt struggles to catch up. Hunt wins the Spanish Grand Prix, but is disqualified after a post-race inspection rules that his car is fractionally too wide. Struggling to comply with F1 rules, McLaren suffers a series of racing setbacks, and Hunt’s situation is further exacerbated when Suzy starts a relationship with actor Richard Burton. Following his divorce, Hunt regains his competitive spirit and, when his disqualification in Spain is overturned, the points put him into championship contention. Lauda marries Marlene in a private ceremony but begins to have concerns about the effects of his newfound happiness, worrying that he has become vulnerable as a racer, as he now has something to lose.
At the German Grand Prix, Lauda urges the F1 committee to cancel the race due to heavy rain on the already notoriously dangerous Nürburgring Nordschleife. At a drivers’ meeting on race day, Hunt argues that Lauda is trying to benefit by having one less race in the season, and the drivers vote to race. Most drivers start the race with wet weather tyres, which becomes a costly tactic due to most of the track quickly drying. They all change tyres during the second lap, but on the third lap, a suspension arm in Lauda’s Ferrari breaks, sending the car flying into an embankment then bursting into flames. Lauda is airlifted to hospital with third-degree burns to his head and face and internal burns to his lungs. For six weeks, Lauda is treated for his injuries while he watches Hunt dominate the races in his absence. Despite his doctor’s orders, he decides to return to drive his Ferrari at the Italian Grand Prix, finishing fourth while Hunt fails to finish.
The 1976 season comes to a climax at the rain-soaked Japanese Grand Prix. Hunt’s late rally in Lauda’s absence has pulled him within three points of Lauda. At the end of the second lap, after his car has slid several times, Lauda returns to the pits and decides to retire from the race, considering it far too dangerous and opting to stay with Marlene instead. This gives Hunt a chance to win the championship if he can finish third or better. After facing stiff competition under gruelling conditions, tyre problems and a hand injury due to the gear shifter knob breaking, Hunt finishes third, winning the championship by a single point.
Hunt spends the rest of the year revelling with fame, sex and drugs, while Lauda takes an interest in flying private planes. At a private airfield in Bologna, Lauda suggests to Hunt that he focus on the next racing season to defend his title, but Hunt argues that his glamorous lifestyle is the most enjoyable part of being world champion. Lauda later on realises that Hunt no longer feels he needs to prove himself to anyone. Hunt continues to race until his retirement in 1979, and becomes a motorsport broadcast commentator until his death in 1993 at the age of 45. Lauda reflects on how their great rivalry and personality differences spurred each other on to their finest achievements, and states that Hunt was the only other driver he ever envied.