The Plymouth Road Runner is a muscle car introduced by Chrysler in the United States for the 1968 model year and marketed under its Plymouth brand. Initially based on the Belvedere, the brand's basic mid-size model, the Road Runner combined a powerful engine with a spartan trim level and a price that undercut increasingly upscale and expensive muscle cars such as the Pontiac GTO and Plymouth's own GTX. It was initially a sales success.
The Road Runner was built in three generations on the mid-size B platform. Like most muscle cars, its performance and sales declined in the 1970s due to an increasing focus on fuel economy and the adoption of more stringent U.S. emission standards. The nameplate became to a trim package for the compact Plymouth Volaré for model year 1976—no longer offering any special performance capability—and was discontinued in 1980.
--copied from Wikipedia
