Muscle car is a term use to refer to a variety of high performance automobiles. The term principally refers to American, Australian and to a lesser extent South African models from the late 1960s and early 1970s and generally describes a 2-door rear wheel drive mid-size car with a large, powerful V8 engine and special trim, intended for maximum torque on the street or in drag racing competition. It is distinguished from sports cars, which were customarily considered smaller, two-seat cars, or GTs, two-seat or 2+2 cars intended for high-speed touring and possibly road racing. High-performance full-size or compact cars are arguably excluded from this category, as are the breed of compact sports coupes inspired by the Ford Mustang. Other factors used in defining classic muscle cars are their age and country of origin. The term "muscle car" did not enter common usage until after production of the cars had essentially ended. It is generally accepted that popular, widespread usage of the term took hold by the early to mid-1980s. During their heyday, print media usually referred to this class of vehicle as "supercars".