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How Muscle Cars Work


The Death of Muscle Cars

In many ways and for many reasons, America lost its innocence in the 1960s, and no-holds-barred performance cars were just one casualty of wrenching social changes. Muscle cars began fading away in the 1970s. Most were gone by mid-decade, victims of a changing market and increasingly strict government regulations. A precious few managed to hang on longer, but only as meek reminders of their '60s selves.

The decline was perhaps inevitable. Demand for big, fast, thirsty cars dried up as rising gas prices and hefty insurance premiums had many buyers looking at thriftier, more affordable Detroit compacts and imported minicars. At the same time, progressively tighter limits on tailpipe emissions forced automakers to detune engines via lowered compression ratios, fewer carburetors, more restrictive intakes, and other power-sapping measures. New Federal Motor Vehicle Safety Standards called for adding crash-protection features such as bigger, sturdier bumpers that added performance-sapping weight.

While these harsh realities compromised all cars to some degree, muscle machines fared the worst by far. They did, after all, have the most to lose.

The Last Great
Muscle Cars
For profiles, photos, and specifications of some of the last great muscle cars of the classic period, see:

Signs of loss appeared as early as 1971, when General Motors' engines and some Chrysler Corporation mills were recalibrated to run on regular-grade gas instead of premium. That same year, GM switched its advertised engine ratings from gross figures to more-realistic net numbers, which made the power and torque losses look even worse on paper. American Motors, Chrysler, and Ford followed suit for 1972, when many engines were further detuned for newly required low-lead fuel.

Then, in October 1973, the Organization of Petroleum Exporting Countries (OPEC) drastically curtailed oil exports to the United States, touching off a national energy crisis marked by widespread fuel shortages, record gas prices, and long lines at the pumps, among other discomforts.

Though the crisis lasted but a few months, it exposed America's growing dependence on foreign energy sources that might not be so predictable. It also rattled Congress into enacting a Corporate Average Fuel Economy law (CAFE), starting with 1978 models that required automakers to meet progressively higher minimum-mpg targets against the threat of hefty fines.

With all this, plus inflation-fueled "sticker shock" price increases, demand for muscle cars decelerated fast. By 1975, the casualty count included most big-block engines and such icon performers as the Buick GS, Chevrolet Chevelle Super Sport, Dodge Charger R/T and Super Bee, Ford Torino Cobra, Mercury Cyclone Spoiler, and Plymouth GTX. Even the hallowed GTO wasn't spared, reduced for 1974 to a largely dress-up option for Pontiac's Ventura compact before the name was belatedly retired. Other heavy-hitters, such as Plymouth's Road Runner, shifted steadily from go to show.

1978 Plymouth Road Runner
©2007 Publications International, Ltd.
This 1978 Plymouth Road Runner was a mere shadow
of the
classic Road Runners from the late 1960s.

Pony cars all but disappeared, with only the Chevy Camaro and Pontiac Firebird left to carry the torch after '74. Ford's Mustang, the original pony, was super-sized for 1971-73, then re-imagined as a high-class economy compact. This Mustang II was fortuitously timed and very popular, but made Mustangers wince even after an optional 302 V-8 returned after a year's absence. Mercury's Cougar? Morphed into obscurity a luxury intermediate.

But it wasn't all bad news. Despite the increasingly hostile climate, a few '70s cars did offer performance kicks, if not the tire-shredding thrills of old.

Heading the list of performance survivors were the "mini-muscle" compacts that began appearing in the early '70s. Sometimes called "insurance beaters," they offered satisfying go from torquey small-block V-8s yet cost far less to buy and operate than '60s-style midsizers.

For example, the 1971-73 Plymouth Duster 340 and Dodge Demon/Dart Sport 340 offered up to 240 net bhp, plus nifty fastback coupe styling, eye-grabbing colors, and enough tape stripes and black accent paint for a Trans-Am race car. A 360 V-8 came in for '74, but for easier emissions tuning, not extra power. American Motors, Ford, and GM offered their own sporty compact confections, and though none sold that well, they brightened up an increasingly gloomy market.

So, too, the top-performing Pontiac Firebirds. Though strangled no less than other hot cars, the Firebird Trans Am and 400 bucked the market by posting higher year-to-year sales for 1973 and '74 -- just as the gas crisis was raging. Of course, it helped they had little competition by then. Still, such surprisingly strong sales convinced product planners all over Detroit that people still craved performance, especially if straight-line speed was balanced by genuine roadability, something mostly unknown in classic muscle cars.

In any case, Chevy took the hint and reinstated the Camaro Z-28 for 1977 after a two-year furlough -- and with a new emphasis on handling. GM also kept its pony cars going with remarkably adept updates to their basic "19701/2" design, meeting federal safety standards with savvy style, not short-cut clumsiness.

Meantime, the economy fast pulled out from its gas-crisis doldrums, and the 1980s approached with signs that Detroit had learned to live with "Fed regs," thus promising a return to real style and performance at last.

Perhaps the most encouraging marker was a clean-sheet 1979 Mustang and companion Mercury Capri: roadable, slick-looking new-think pony cars that admirably reconciled many conflicting demands of the day. The base engine was an economy-minded four with just 88 net bhp, but you could order 140 horses with either a turbocharged four or that old standby, Dearborn's 302 V-8. The latter returned 0-60 mph in about 8.7 seconds. That was a bit adrift of the lighter Mustangs with turbocharged four-cylinder engines, but buyers showed a marked preference for good old low-rpm V-8 torque, another fact not lost on product planners. Could a new performance era be ahead? It certainly seemed so.

Then, in spring 1979, came a second gas crunch that had buyers scurrying back to smaller cars again. Though Detroit had been "downsizing" its fleet to meet fuel-economy targets, it was tough to know how this new crisis would play out. Engineers were fast developing technology for doing more with less, but did performance have a place in this brave new world? Or would a new generation of car buyers, many weaned on economy imports, be looking for something else entirely?

On the next page, you'll see that the answer to both questions was yes. People still wanted hot cars, but not the kind their fathers knew. Times had changed. But Detroit had changed, too, and was ready to spring some surprises. The muscle car was about to be reborn.

Return to Muscle Car Information Library.

For related car information, see these articles:

  • The engine is what gives a muscle car its flamboyant personality. To learn everything you need to know about car engines, see ­How Car Engines Work.
  • Muscle cars wouldn't have much muscle without horsepower -- but what exactly is horsepower? How Horsepower Works answers that question.
  • NASCAR race cars embody the muscle car philosophy of power. Read How NASCAR Race Cars Work to find out what makes these charged-up racers go.
  • Are you thinking of buying a 2007 muscle car, or any other car? See Consumer Guide Automotive's New-Car Reviews, Prices, and Information.


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