The term muscle car generally describes a mid-size car with a large, powerful engine (typically, although not universally, a V8 engine) and special trim, intended for maximum acceleration on the street or in drag racing competition. It is distinguished from sports cars, which were customarily and coincidentally 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 and typically known as pony cars, although few would dispute a big-block pony car's credentials as a muscle car.