Super-iority: Defining the Supercar and Muscle Car

One of the minor but contentious arguments among automotive enthusiasts and historians is the question of exactly what constitutes a muscle car. Since we’ll be talking about several cars of this breed in the coming weeks, we thought we’d give you our take on this issue.

1967 Oldsmobile Cutlass 442 nose low
A 1967 Oldsmobile 442. Oldsmobile’s answer to the Pontiac GTO, the 442 was launched in 1964 with a 330 cu. in. (5,404 cc) engine, a four-barrel carburetor, four-speed manual transmission, and dual exhausts. By 1967, the definition of 442 was 400 cubic inches (6,554 cc), a four-barrel carburetor (although a three two-barrel setup was briefly offered in 1966), and dual exhausts.

The conventional wisdom defines “muscle car” as a performance-oriented American midsize car (usually limited to those built between 1964 and 1973) with a big-displacement engine, inspired by the 1964 Pontiac GTO. Naturally, by the standards of the rest of the world, most American V8s of the period were enormous, but in domestic terms, “big” meant a displacement of at least 370 cubic inches (6 liters, give or take). Similarly, “midsize” was only by comparison with other domestic automobiles, which still meant a wheelbase of 112 to 118 inches (2,845 to 2,997 mm) and an overall length between 190 and 210 inches (4,826 to 5,334 mm).

“Performance-oriented” also demands some qualification. By the late sixties, every U.S. state except Nevada had zealously enforced speed limits of 70 mph (113 km/h) or less, so top speed was not terribly relevant to American drivers. Handling and braking were not high priorities, either, and many of these cars scored poorly in those areas. “Performance,” therefore, meant acceleration, both 0-60 mph (0-97 km/h) and the standing quarter mile (about 400 meters, for our metric readers). The minimum for muscle car status was an elapsed time of less than 16 seconds with trap speeds of more than 90 mph (145 km/h), although some models were naturally much quicker than that.

The trouble with this definition is that there are a lot of potential loopholes. For example, do compacts like the Chevrolet Nova SS count? They had the performance, but they were not midsize cars by the standards of the time. What about a big-engine Ford Mustang or Chevrolet Camaro? Or latter-day cars like the Buick Regal Grand National and GNX (the subject of an upcoming article), which achieved V8-size performance with a turbocharged six-cylinder engine? What about big-block Corvettes?

Our preference is to follow contemporary usage. The term “muscle car” did pop up periodically, most commonly in Road Test magazine (where it was not intended as a compliment), but it was not widely used in the period when these cars were new. The term only really caught on years after most of the original examples were extinct. From the mid-sixties to the mid-seventies, what we now think of as muscle cars were more commonly called “Supercars,” often (though not always) spelled with a capital S.

1964 Pontiac GTO side
There are earlier cars that would fit the definition of “muscle car” or “Supercar” (the 1949-50 Oldsmobile Rocket Eighty-Eight springs to mind), but the car that defined the class was the 1964 Pontiac GTO. An option package for the new A-body Tempest, it featured a big 389 cu. in. (6,372 cc) engine and up to 348 gross horsepower (260 kW). A great marketing success, it was followed by many imitators.

Contemporary sources applied that term fairly broadly, without the hair-splitting that seems to obsess modern enthusiasts. The term originated to describe the many imitators of the Pontiac GTO, so most of the members of this class were indeed big-engine intermediates. However, the main qualifiers were performance and sharing a body shell with standard passenger cars — the “Clark Kent” models, if you will.

In our observation, contemporary sources had no particular problem classifying a sporty, small-block compact like the Plymouth Duster 340 as a Supercar if it had performance to match. Full-size models like the short-lived Mercury Marauder X-100 were a hazier issue, but would probably have qualified as well. The only reason their status was ambiguous was that by the late sixties, hot full-size cars like the Chevrolet Impala SS had been so eclipsed in sales and performance by their smaller brethren that they were almost irrelevant. They were no longer promoted and rarely even road tested by popular magazines. You could still order an Impala SS427 through 1969, for example, but Chevrolet sold fewer than 2,500 of them that year compared to more than 86,000 mid-size Chevelle SS models.

In this era, the Ford Mustang and its imitators were not generally considered Supercars (except by insurance companies) — not because of their performance, but because they had unique bodies. Mustang-type cars shared many components with more mundane passenger cars, but they had their own body shells. Contemporary sources usually call such cars “sporty cars” or occasionally “pony cars.”

A two-seater like the Chevrolet Corvette (and later, grudgingly, the AMC AMX) was considered neither a Supercar nor a sporty car; it was a sports car. The same went for the early GT-350 Mustang, whose transformation from sporty car to sports car was accomplished by the simple expedient of unbolting and removing the Mustang’s rear seat. European sports car enthusiasts scoffed, but if it was good enough for the Sports Car Club of America (SCCA), it was good enough for most domestic journalists.

1968 AMC AMX front 3q
The 1968-1970 AMC AMX was a shortened version of the AMC Javelin sporty car shorn of 12 inches (305 mm) of wheelbase and bereft of its back seat.

In these articles, we generally try to follow the lead of contemporary sources, so we prefer “Supercar” and “sporty car” to “muscle car” and “pony car.” (We’re more likely to use “pony car” than “sporty car” just because it helps to distinguish Mustang-type vehicles from, say, a Dodge Charger or an AMC Rambler Marlin, which did not share the same body shell as their passenger-car cousins, but were clearly in a different size and price class from the Mustang.)

We are hesitant to apply the term Supercar to more modern vehicles, both because the term has come to connote exotic sports cars rather than souped-up passenger cars and because the standards of performance have shifted radically. “Muscle cars” became legendary because for many years, such straight-line performance was quite rarefied. Today, a lot of sixties Supercars could be embarrassed by any number of six-cylinder family sedans, at least in stock form. Furthermore, in a marketing sense, the clearest spiritual heirs to the Supercars are models like the Honda Civic Si and Chevy Cobalt SS, although lumping them in with the vintage GTOs and Road Runners would please fans of neither. We will make occasional exceptions (if you want to call the 2004–2006 Pontiac GTO a Supercar, we certainly aren’t going to argue), but in general, our goal is to put things into their proper historical context, not to make editorial comments about their worth.

Future arguments, like whether a car with a turbocharged V6 can be a muscle car, will be referred back here…




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  1. Oh my, this series should be interesting. I hope there are at least some references to penal and penile dysfunction; as a whole muscle cars were pre-steroid examples of just rolling macho bravo. Hard to steer, shift, or stop. They were uncomfortable, noisy and politically incorrect even then. Put on the racing stripes and man were you “cool.”

    This will be as embarrassing as looking at old high school photographs. The 1967 Olds 442 HO 0-60 was clocked in at 7.8 seconds and I see the current Toyota Yaris does that in 10.8, with an automatic much less. What were we thinking? Vroom vroom.

  2. Hello there!
    You guys know it for sure but anyway I should say that you are doing wonderful job with this web-site. Comparision with AQ magazine even springs to mind. Keep the good work!
    Also I have a question for you. I was under impression that the first digit in Olds 442 stands for 4-on-the-floor i.e. 4 speed manual gearbox mounted on the floor. My mistake?

    1. When the 4-4-2 was first introduced in 1964, the digits did indeed mean four-speed, four-barrel carburetor, and dual exhaust. When it switched to the big block 400 cu. in. engine in 1965, however, it became available with a three-speed manual or a two-speed automatic — which would have been a 342 or a 242, by that logic. So, Olds declared that the first “4” meant “400 cubic inches.”

      You can find out more in our article on the 4-4-2:

  3. Thanks for clearing the matter! I wish I could see as many beautiful cars on the streets everyday just as you do. Never saw Olds in person apart from Alero, Bravada and Cutlass Ciera. Well one day may be… :)

    1. It is remarkable. Just the other day, for instance, we stumbled on a lovely Mercedes 190SL, which will be the subject of an article in September.

  4. All this talk about what was the “original” muscle car, and always revolving around the GTO…..

    ….back in 1958, I had a Plymouth Fury (remember the movie Christine?), that would blow the doors off anything on the street, then, as well as most of what came out of Detroit’s locker-room well into the mid to late 60’s.

    I’m sure there were plenty others as well, that would qualify as genuine “muscle-cars”, long before the GTO hit the streets.

    Problem is, we never hear much about them, do we?

    1. From an engineering or conceptual standpoint, the GTO was in no way a new idea. The idea of putting a larger engine in a lighter/smaller car was old in 1963, or in 1958. Even before getting into fifties special editions like the Studebaker Golden Hawk or the original Fury, there were cars like the 1932 Essex Terraplane (which used the larger six of the Essex Super Six in a smaller and considerably lighter chassis) and the original Buick Century (which used the engine from the Roadmaster and Limited in the chassis of the Special).

      Where the GTO is significant, and really unavoidable, is that it was a hugely successful piece of merchandising. A 1962 Plymouth Belvedere was basically a midsize car, and a lightly optioned 413 would be a formidable opponent for an early GTO; however, the ’62 Mopars weren’t marketed as performance cars, and they were a sales disaster. Because the GTO was a hit, it spawned a whole genre of direct imitators.

      A good comparison would be the movie [i]Star Wars[/i]. [i]Star Wars[/i] was hardly the first science fiction movie, or even the first big-budget science fiction movie. Creatively, it was a hodgepodge of influences, some acknowledged (Flash Gordon, Kurosawa’s [i]The Hidden Fortress[/i]), some not {[i]Lensman[/i], Jack Kirby’s [i]Fantastic Four[/i] and [i]New Gods[/i]). However, because it became a box office and merchandising bonanza, it sparked a legion of direct imitators, and it led to even some pre-existing entertainment properties being made over to “be more like [i]Star Wars[/i].” Thus, even though it wasn’t really the first of anything in a technical sense, it provided the template for the genre.

      The GTO was the same way. Merchandising people are rarely concerned with — or even aware of — historical precedents; they think in terms of “get me another hit like X.” If the GTO had been a commercial flop, it would be as forgotten as the Terraplane, and maybe something else would have taken its place. Hard to say.

    2. I think you could include the ’36-42 Buick Century, and possibly the ’54-56 Century as well in this category.

      Also the ’49-50 Olds 88, although with only 135HP that might be a stretch.

      These both fit the formula of a smaller body with the powertrain from the upscale larger body car of the same make, and in their time, they outperformed most other factory stock cars

      1. For the time, the Oldsmobile Rocket 88 certainly qualified, although it was of course mild by subsequent standards.

  5. Hi, I love your articles- esp the ones on American Cars.
    However I would dispute that ‘Road Test’
    coined the term in 1967. I have an
    article from "Road & Track" from July 1965.

    The article’s title is "The Musclecars" Covers the GM A bodies, and Dodge Coronet and Plymouth Belvedere. Interesting to note that no fomoco products are mentioned……..

    Thanks again and keep up the good work. I don’t
    suppose an article about the Holden HQ is in the pipeline- a favourite of mine!

    1. In July 1965 the 1966 Fairlane and Comet (with 390CI engines) weren’t out yet. So the top engine in the 1965 FoMoCo products would have been the K code 289 which was not quite in the same league with the GM A-bodies or the Chrysler B-bodies, all of which had 383 CI engines or larger. Ford wasn’t in the intermediate muscle car market in 1965.

  6. My view of what defines a “muscle car” (and a lot of fellow Brits as well) is a car that has ferocious acceleration without much regard for any other driving dynamics.
    The concept of a large engined small car never really caught on in Europe, with our narrow twisting roads and high gas prices they didn’t have much appeal to mainstream car buyers. Large engines were found in large upmarket cars, mainly because fuel economy was a major factor for us.
    Cornering ability, handling and braking were always a major consideration, much more so than in North America.
    As a consequence most manufacturers offered instead faster versions of their mainstream cars – often badged as “GT” versions. The main differences from the standard cars were the engine in a higher state of tune, stiffer suspension, wider tires and often more gauges, especially a rev counter. this kept weight down, resulting in a car that was both faster and better handling in most cases at the expense of reliability and ride comfort.

    Supercars as I understood the concept were the cars designed from the outset to be immensely fast, 150mph+ top speed was a general benchmark, with large powerful engines coupled with sophisticated suspension that could handle the power. Ferrari, Lamborghini Aston Martin and possibly the E type Jaguar were examples of the breed, Jensens had vast (by our standards!) American V8 engines but were not so great at high speed handling apart from the complex FF versions you mentioned in one of your excellent articles.

    The 3 liter Ford Capri was the only British car that came close to a muscle car in my opinion, Triumphs Vittese and the Vauxhall Viva GT put larger engines in cars really designed for smaller units, but in both cases they were no faster in a drag race than most similarly priced cars.


    1. Roger,

      The average American today would have much the same definition of “muscle car” or “Supercar” as you describe — my point is that the present usage of those terms is of more modern origin. At least in the States, the term muscle car was not widely applied to these cars when they were new. Conversely, the term Supercar wasn’t yet widely applied to exotica like the Miura or 365GTB/4 Daytona, in part because, I believe, they hadn’t yet made a big impression on American youth. Until the prices and insurance rates became prohibitive, the average young American car nut was more focused on performance cars one could actually save up his or her pennies and buy. Once the muscle cars became more or less extinct by about 1974, there was more room for European exotic sports cars as fantasy objects.

      The Capri is an interesting case because conceptually it was essentially a European spin on the pony car concept popularized by the Mustang. As the article says, the distinction was that a Supercar was a hotted-up version of a fairly ordinary two-door sedan, hardtop, or convertible, while a pony car was a sporty 2+2 coupe sharing the running gear of a cooking sedan (in the Capri’s case, the Cortina), but with a unique body shell. There were certainly pony cars that were in the same performance realm as contemporary intermediate Supercars, but calling something like a big-engine Mustang a muscle car is still a good way to start a pub argument with a certain category of people. With the Capri, you could obviously make a case that the V6 cars qualified as muscle cars, at least by European standards, but applying that term to a Capri 1600 or 2000 would be a stretch, and so it is with, say, an early six-cylinder Mustang (which could conceivably be out-dragged by a Mk 1 Escort 1300GT, 3.3 liters or no).

      The social role of the American Supercar in its native habitat and era was actually quite similar to that of the hot hatches that became the rage for British and European youth in the ’80s. The hot hatches aspired to a broader performance lexicon (in part of necessity — even if Ford or Opel/Vauxhall had been able to stuff a 7-liter V8 into a Cortina, Ascona, or Cavalier, hardly anyone could have afforded to buy one, so that approach clearly wasn’t on), but both were essentially merchandizing concepts: ways for manufacturers to add some excitement to ordinary family cars for a relatively modest investment.

      1. The U.S., of course, also benefited from having an abundance of relatively inexpensive, well-developed, and fairly efficient big modern engines. (Even a 6.4-liter Pontiac V-8 wasn’t much if any heavier than a BMC C-series six, could yield more than twice the horsepower, and was relatively cheap because it also went into hundreds of thousands of quite ordinary Pontiac family cars.) In the U.K., the options in the “big stonking engine” category were not abundant, and of those that did exist were either too expensive or not really powerful enough to be worth the bother.

  7. Are there going to be anything more for this? It seems very incomplete to me.

    Or is it sort of cancelled?

    1. Any more in what sense? This was an editorial on the use of the term, not a survey of muscle cars or anything like that. It was written right before the GTO, Grand National/GNX, and AMC SC/Rambler stories (which are now linked in the text), and since then there’s been the Cutlass/442, Hurst/Olds, second-generation Charger, Javelin, and Buick Gran Sport, so there hasn’t been any shortage of muscle cars. If you click the Model Histories button on the navigation bar, you can look through the sports/muscle car stories, sorted by year.

  8. I think I’ve encountered the argumentative people you so cautiously circumscribe here. I’ve met them on the internet – the online presence of Hemmings Muscle Machines seems to be their haven – and at some car shows I’ve visited.

    Narrow minded bunch of old… gentlemen in my opinion. They seem to be unable to enjoy a vintage car if it’s not one of a handful of revered models that’s factory correct down to the last nut and bolt. Unless you own a Ram Air IV GTO or 427 Galaxie on bias-ply tires, you’ll either hear tall tales of how they used to own a car that could totally smoke yours, which apparently somehow invalidates your choice, or being admonished for some minute detail on your car being “wrong”, which I guess means you’re a fool with no respect for the classics.

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