The series was founded in 1972, and was called "showroom stock." A revised version of the series came about in 1984. In 1985, the series got an odd title sponsor — the magazine Playboy. Escort radar detectors also sponsored the series from 1986 — 1989.
Each season usually consists of 10 rounds, with each class running a race at separate times. Each round is started from a standing start, as opposed to a rolling start as seen in NASCAR or the American Le Mans Series.
The series is named for the network that broadcasts it: SPEED Channel. When SPEED Channel was SpeedVision, it was called the SpeedVision World Challenge. SPEED Channel commentator Leigh Diffey was the voice of the series until the end of 2004. Beginning in 2005, Diffey was replaced by Greg Creamer.
Each race has a 50 minute time limit.
Grand Touring (GT): Includes a variety of production displacements with no maximum. Forced induction is permitted and is used to equalize individual models. Sedans, coupes, convertibles and two-seat models are permitted. The cars can be rear-wheel, or all-wheel drive. Class horsepower range is 350 - 550 bhp.
Touring Car (TC): Cars up to 2.8-liters that are naturally aspirated are permitted. Forced induction permitted as if it came that way from the factory. The cars can be front-wheel, rear-wheel, or all-wheel drive. The cars must be able to seat four adults, and convertibles are not allowed. Class horsepower range is 240 - 290 bhp.
|Date||Location||Classes||GT Winner||Touring Car winner|
|March 14||Sebring Raceway||GT||TC||Randy Pobst||Pierre Kleinubing|
|April 20||Long Beach||GT||Brandon Davis|
|April 27||Virginia International Raceway||TC||Kuno Wittmer|
|May 18||Miller Motorsports Park||GT||TC||Tommy Archer||Jason Saini|
|May 24||Lime Rock Park||TC||Kuno Wittmer|
|May 26||Lime Rock Park||TC||Chip Herr|
|June 8||Watkins Glen International||GT||TC||Randy Pobst||Michael Galati|
|July 20||Mid-Ohio Sports Car Course||GT||TC||Tommy Archer||Kuno Wittmer|
|August 10||Road America||GT||TC||Tommy Archer||James Clay|
|August 24||Mosport||GT||TC||Eric Curran||Michael Galati|
|August 30||Belle Isle||GT||Randy Pobst|
|September 28||New Jersey Motorsports Park||GT||James Sofronas|
|October 3||Road Atlanta||GT||TC|