Muscle Car - Decline

Decline

The muscle car market segment was in high gear "until shifting social attitudes, crippling insurance rates, the Clean Air Act and the fuel crisis removed the cars from the market in the early 1970s." The OPEC oil embargo led to price controls and gasoline rationing, as well as higher prices. "Muscle cars quickly became unaffordable and impractical for many people." The automobile insurance industry also levied surcharges on all high-powered models, an added cost that put many muscle cars out of reach of their intended buyers. Simultaneously, efforts to combat air pollution—a problem that grew more complicated in—focused Detroit's attention on emissions control.

A majority of muscle cars came optioned with high-compression powerplants-some as high as 11:1. Prior to the oil embargo, 100-octane fuel was common (e.g. Sunoco 260, Esso Extra, Chevron Custom Supreme, Super Shell, Texaco Sky Chief, Phillips 66 Flite Fuel, Amoco Super Premium, Gulf No-nox); however, following the passage of the Clean Air Act of 1970, octane ratings were lowered to 91-due in part to the removal of tetraethyllead as a valve lubricant. Unleaded gasoline was phased in as a result.

With all these forces against it, the market for muscle cars rapidly evaporated. Horsepower began to drop in 1971 as engine compression ratios were reduced. High-performance engines like Chrysler's 426 Hemi were discontinued, and all but a few of other performance models were discontinued or transformed into soft personal luxury cars. Some nameplates, such as Chevrolet's SS or Oldsmobile's 442, would become sport appearance packages (known in the mid to late 1970s as the vinyl and decal option-Plymouth's Road Runner was an upscale decor package for their Volare coupes). One of the last to be discontinued, a car that Car and Driver called "The Last of the Fast Ones", was Pontiac's Firebird Trans Am SD455model of 1973–1974. In 1975 its performance was markedly reduced.

American performance cars began to make a return in the 1980s. Owing to increases in production costs and tighter regulations governing pollution and safety, these vehicles were not designed to the formula of the traditional low-cost muscle cars. The introduction of electronic fuel injection and overdrive transmission for the remaining 1960s muscle car survivors, such as the Ford Mustang, Chevrolet Camaro and Pontiac Firebird, helped sustain a market share for them alongside personal luxury coupes with performance packages, such as the Buick Regal T-Type or Grand National, Ford Thunderbird Turbo Coupe and Chevrolet Monte Carlo SS circa 1983-88.