The term muscle car is primarily used for a high-performance 2-door rear wheel drive mid-sized cars fitted with big and powerful V8 engines. A muscle car will typically have special trim and be intended for maximum torque. A muscle car is not the same thing as a sports car; muscle cars tend to be bigger and they will often have more than two seats. High-performance full-size or compact cars are rarely referred to as muscle cars, and the same is true for the Ford Mustang inspired compact sports coupes.
The main producers of muscle cars are the United State, Australia and South Africa. A majority of the cars referred to as true muscle cars were produced from 1964 to 1974. Interestingly enough, the term muscle car was not commonly used during this era; it became popular when the production of these legendary muscle cars had more or less ended.
Some car enthusiasts use the power-to-weight ratio to define which cars that are true muscle cars and which ones that are not. According to this definition, a muscle car can not exceed a certain amount of lb (or kg) per rated 1 horsepower (0.7 kW). If the number of lb (kg) per rated 1 horsepower (0.7 kW) exceeds a certain number, the car is not considered a muscle car.
The required power-to-weight ratio varies among the muscle car aficionados and it is therefore impossible to provide an exact number.
The history of the muscle cars started after World War II when major automakers in the United States once again began focusing on performance. The Chrysler 300 letter series from 1955 is an important milestone and is considered by many to be the early ancestor of all the American muscle cars. Compared to later muscle cars, the Chrysler 300 letter series was however made up by really big, luxurious and expensive cars.
After the introduction of the big Chrysler 300 letter series cars, the idea of using powerful engines for ordinary mid-sized cars soon arose among the American car manufacturers. The American Motors Corporation (AMC) started by creating a factory hot-rod hardtop sedan fitted with a 327 cu in (5.4 L) V8 engine and a 4-barrel carburetor. This engine was capable of producing 255 horsepower (190.2 kW). The Rambler Rebel from AMC was produced from 1957 to 1960, and then again from 1966 to 1967.
During the early 1960s the muscle cars become more and more popular on the United States market and several car companies developed their own muscle cars. Among these early muscle cars you will for instance find the 1962 Dodge Dart 413 in³ (6.8 L) Max Wedge and the 1964 427 in³ (7.0 L) Thunderbolt from Ford. Throughout the early 1960s, Ford and Mopar (Dodge, Plymouth, and Chrysler) continuously combated each other on the American muscle car market.
One of reasons why the muscle cars became so popular in the United States during the 1960s is probably the fact that they managed to combine strong street performance with a comparatively low price. This meant that a muscle car could be afforded even by fairly young drivers. As the muscle car evolved, the price did however increase dramatically as the producers all strived to make the cars bigger, more lavishly styled, and offered with a vast array of optional equipment. All the extra weight made it necessary to add increasingly powerful engines, which in turn had a significant effect on the price of the muscle cars. In 1967 and 1968 several so called “budget muscles” were introduced in order to attract customers that could no longer afford ordinary muscle cars. Among these budget muscle cars were the famous Dodge Super Bee and Plymouth Road Runner.
While the muscle cars were experiencing their heydays in the United States, Australia developed its very own muscle cars. The first Australian muscle car was introduced in 1967, a 287 cu in (4.7 L) Windsor–powered XR Falcon. Today, the most highly sought after Australian muscle car is the 351 cu in (5.8 L) Cleveland-powered Ford Falcon GTHO Phase III of 1971.
The first South African muscle car was created by Chevrolet who managed to fit a Vauxhall Viva coupe bodyshell with a Z28 302 Chevrolet smallblock engine. The result was the Firenza CanAm.