What is it?
The National Association for Stock Car Racing was born out of attempts in the 1920s and 1930s to set land speed records on Daytona Beach in Florida. Yesterday marked the start of the Daytona 500 which marks the beginning of Nascar's 60th season.
How is it different to other motor sports?
The cars are essentially souped-up versions of everyday vehicles. More so than other sports it is a war of attrition: most of the 36 races are run on ovals where speeds reach 200mph and crashes are frequent. The 75 million-strong blue-collar fan base is thought to be the most loyal of any sport, buying over $3bn (£2.1bn) in licensed products annually.
What has been the effect of the global recession?
The ailing US car industry has hit Nascar hard. Corporate sponsorship has dried up, ticket sales have slowed and teams are folding or being forced to merge. For the first time in 60 years no driver named Petty started yesterday. Dale Earnhardt Inc, founded by the eponymous seven-times champion, has been forced to merge with Chip Ganassi's team to form Earnhardt Ganassi Racing. The legendary Wood Brothers are only racing a partial schedule.
Who are the biggest stars?
Names such as Petty and Earnhardt have had a grip on the national imagination for generations. More recently, former Formula One drivers such as Juan Pablo Montoya have brought in sponsorship from rival sports.
How can I watch it?
Extended coverage on Sky Sports Xtra from midday today. Channel 5 also has a highlights programme.