Grand National

From 1950 through 1971, the top tier NASCAR series was called the Grand National, not to be confused with the later Busch Grand National Series (now simply the Busch Series), the second tier division of NASCAR.

Winston Cup

From 1972 through 2003, NASCAR's premier series was called the Winston Cup Series. It was sponsored by R.J. Reynolds Tobacco (RJR) as an advertising mechanism to bring attention to its Winston brand of cigarettes. In its later years, RJR's sponsorship became more controversial in the wake of US legislation that sharply restricted avenues for tobacco advertising.

NEXTEL Cup

In 2003, RJR dropped its sponsorship of the top series, and NASCAR obtained a sponsorship from NEXTEL, a telecommunications company. Starting in 2004, the premier series was known as the NEXTEL Cup.

The merger between Sprint and NEXTEL will potentially result in the series being renamed Sprint Cup in 2007, although it is still being discussed and debated by all involved parties.