A breed of powerful hybrids appeared in the 1950s and 1960s and raced on both sides of the Atlantic, featuring European chassis and large American engines – from the earlyAllard cars via hybrids, such as Lotus 19s fitted with large engines, through to the AC Cobra. The combination of mostly British chassis and American V8 engines gave rise to theCan-Am series in the 1960s and 1970s. This series, based in the United States and Canada, featured lightweight prototype sports cars fitted with large, powerful production-based engines that produced speeds in excess of 200 mph. Clubmans provided much entertainment at club-racing level from the 1960s into the 1990s, and John Webb revived interest in big sports prototypes with Thundersports in the 1980s. Group 4 Grand Touring Cars and Group 5 Special Production Cars became the premier form of sports car racing from 1976, with prototypes going into a general decline apart from Porsche 936 domination at Le Mans and a lower-key series of races for smaller two-litre Group 6prototypes. The last NASCAR race on a dirt track was held on September 30, 1970 at the half-mile State Fairgrounds Speedway in Raleigh, North Carolina. From 1972 through 2003, NASCAR's premier series was called the Winston Cup Series, sponsored by R. J. Reynolds Tobacco Company cigarette brand Winston. The changes that resulted from RJR's involvement, as well as the reduction of the schedule from 48 to 31 races a year, established 1972 as the beginning of NASCAR's "modern era".
In Europe, the FIA adopted the ACO GTP rules virtually unchanged and sanctioned the Group C World Endurance Championship (or World Sportscar Championship), featuring high-tech closed-cockpit prototypes. In the USA, the IMSA Camel GTP series boasted close competition between huge fields of manufacturer-backed teams and privateer squads – the cars were technically similar to Group Cs but used a sliding scale of weights and engine capacities to try to limit performance. The FIA attempted to make Group C into a virtual "two seater Grand Prix" format in the early 1990s, with engine rules in common with F1, short race distances, and a schedule dovetailing with that of the F1 rounds. The IMSA GT Championship had been prototype-based since 1983, with less emphasis on production cars. Australian Production Car Championship was first contested in 1987, with the inaugural champion determined from the results of two races held at the Winton Motor Raceway in Victoria on September 27. The first World Touring Car Championship, which was open to Group A Touring Cars, was held in 1987 concurrent to the long-running European Touring Car Championship (ETCC). Additional rounds were held outside Europe at Bathurst in Australia, Calder Park Raceway in Australia (using both the road course and the then-newly constructed Thunderdome), Wellington in New Zealand andMount Fuji in Japan. The Drivers Championship was won by Roberto Ravaglia in a BMW M3, and the Entrants Championship was won by the Eggenberger Texaco Ford No 7 entry, which was a Ford Sierra. Winston Cup Series underwent a large boom in popularity in the 1990s.[21] This coincided with a decline of popularity in American Championship Car Racing. The FISA decided to separate the rally cars into three classes: Group N (production cars), Group A (modified production cars), and Group B (modified sport cars). Group B was introduced by the FIA in 1982 as a replacement for both Group 4 (modified grand touring) and Group 5 (touring prototype) cars.
The IMSA GT Series evolved into the American Le Mans Series, which ran its first season in 1999.[22] The European races eventually became the closely related Le Mans Series, both of which mix prototypes and GTs. The SCCA World Challenge consists of a one-hour race for each round, combining three classes: GT (Chevrolet Corvette, Aston Martin DB9, etc.), "GTS" (Acura TSX, BMW 3-series, etc.; replaced the former touring car class), and Touring Car (a "showroom stock" class similar to Grand Am's Continental Challenge). NASCAR was becoming increasingly dominant, and the IndyCar Series' split from CART in 1996 put more emphasis on ovals regarding domestic open-wheel racing.