The 1971-73 Ford Mustang has been widely criticized for growing too big and fat. However, Ford didn’t act in isolation — all of the pony cars saw meaningful increases in size and weight when they were redesigned in the early-70s. Indeed, the Pontiac Firebird was one of the biggest offenders. Model for model, the second-generation Firebird became the heaviest pony car.
The 1971 Mustang added 300 pounds from a comparably equipped 1967 model, but it was still a good 260 pounds lighter than the Firebird, whose redesigned body was introduced in the middle of the 1970 model year.
The above table only shows weights for six-cylinder models. The top-end Firebird Trans Am V8 weighed even more: 3,575 pounds. That was heavier than a Dodge Challenger R/T (80 pounds), Mercury Cougar XR-7 (260 pounds) and AMC Javelin AMX (330 pounds).
Like the rest of the pony cars, the Firebird got heavier partly because it grew in length and width. In addition, the so-called F-body the Firebird shared with the Chevrolet Camaro was also weighed down by new features such as exceptionally long doors, which eliminated quarter windows between the B- and C-pillars.
General Motors’ designers deserve credit for visually minimizing the F-body’s bigger size. This was partly accomplished by unusually curvaceous fender shapes, a gently tapered fastback roofline and a lithe rear end.
This was in stark contrast to Ford designers, who emphasized slab sides, heavy creases and kammback rear ends. The unhappy result was that the Mustang and Cougar looked even more ponderous than they actually were. The most extreme example was the Mustang fastback, with its almost horizontal backlight and a rear end reminiscent of an ice cream truck.
The F-body also hid its width better than Chrysler’s pony car twins. This is particularly apparent in hood treatments. Whereas the Challenger and Plymouth Barracuda both adopted flat hoods and heavily horizontal grilles that accentuated each car’s width, both the Firebird and Camaro included Jaguaresque curves around their single headlights and radiator-style grilles.
I’d argue that the second-generation Firebird and Camaro were the best executed designs in the history of each of these nameplates. Unfortunately, an automotive designer can do only so much with an obese platform. That raises an interesting question: What if one applied the Firebird’s terrific styling to a platform that was similar in size and weight to the original Mustang?
It wouldn’t have taken much to fix the Firebird
The photo below shows the 1970 Firebird from one of its more flattering angles. Nevertheless, the car does not have the lean proportions of a European sporty coupe of that era. Both the front and rear overhangs are too long. Meanwhile, the greenhouse is so low that it has a turret-topped quality, which is exacerbated by the unusually upright A-pillar and an overly long door.
The photoshopped Firebird below addresses all of these issues. The wheelbase ahead of the front wheels is cut by four inches, and both the front and rear overhangs are each trimmed by around two inches. You can’t see it in this side view, but the width is reduced by around 3.5 inches. Meanwhile, the greenhouse is raised roughly an inch and the windshield is given a sharper angle without getting rid of its lovely curvature. Adding quarter windows gives the Firebird an airier and more rounded look.
Pruning the Firebird’s dimensions should have resulted in a corresponding reduction in weight. Even the original Firebird and Camaro were much heavier than the Mustang, so some serious work was needed in this department. If engineers could have reduced the Firebird’s weight by around 300 pounds, it could have been a terrific match with Pontiac’s overhead-cam six, which had been discontinued after 1969.
The OHC six represented only 20 percent of the Firebird’s 1967-68 sales. However, buyer interest might have increased in the early-70s, when a recession led to soaring sales for compact two-door coupes with good fuel economy . . . at the same time that sales tanked for all of those bigger, glitzier and more powerful pony cars. This may help explain why Ford executive Lee Iacocca reportedly stated, “The Mustang market never left us, we left it.”
Pony car sales went down as the bloat went up
The graph below shows how every pony car except for the Mustang saw its output fall below 100,000 units by 1972. The Firebird managed to maintain a fourth-place standing behind the Mustang, Camaro and Cougar, but output fell to less than 30,000 in 1972 — and from 1970-73 averaged under 45,000 per year. Compare that to 1968, when production peaked at over 106,000 units and averaged roughly 92,000 per year between 1967-69.
American automakers must have been nonplussed to see how their costly pony car redesigns were selling so poorly that some may have never turned a profit. This was happening at the same time when the Plymouth Duster — a modest redesign of the aging Valiant — was selling more than 224,000 units per year between 1970-73.
While a goodly portion of those Dusters were strippo models, you could option one to levels approaching that of the 1967-69 Barracuda. A key reason why the 1970-73 Barracuda was one of the worst-selling pony cars could have been because its compact counterpart was arguably a better deal.
Or consider the Ford Maverick. When it was introduced in the spring of 1969, the car was positioned as a bargain-basement import fighter. The Maverick coupe was essentially a shortened and decontented 1969 Mustang. However, the Maverick probably did not cannibalize many Mustang sales because it was such a bare-bones design even with its sporty trim package, the oddly-named Grabber.
That said, Ford sold far more Mavericks than Mustangs during 1970-73: Roughly one million units versus 609,000 units, respectively. Might the Mustang have done better if it hadn’t bloated out so much? Here’s one indicator: Even though 1970 sales were depressed by a recession and an aging design that was overshadowed by GM’s new F-body, the Mustang still sold substantially better than in 1971-73. Bigger didn’t turn out to be a better.
The ‘Sexy European’ upstages American pony cars
This did not fit on the above graph, but another warning sign was the early-70s Mercury Capri, which was Ford of Europe’s interpretation of an American pony car. In 1970, the first year the Capri was imported through Lincoln-Mercury dealers, sales were modest — roughly 17,300 units. However, by 1973 sales had soared to 113,100. Tellingly, in 1972-73 the Capri handily outsold every American pony car except for the Mustang. That was despite an escalating price tag that, by 1973, matched its American competitors even though the Capri was much smaller.
For roughly the same price of a 1973 Capri V6 ($3,261), you could get “a lot more car for your money” — a Firebird V8 in mid-range Esprit or Formula trim. Yet more than twice as many buyers opted for a Capri.
As the 1970s progressed, currency fluctuations ultimately destroyed the Capri’s viability as an import. Meanwhile, GM’s F-body experienced a boomlet in popularity, particularly between the 1973 and 1979 oil crises. In 1977 Firebird output reached almost 156,000 units — a few thousand more than the Mustang II, which in 1974 had been downsized onto the subcompact Pinto platform.
So yes, the Firebird — like the Camaro — went on to have some very good years. Nevertheless, over the last half century the Mustang tended to sell better when it was smaller and lighter than the F-body.
With the 1970 redesign, GM doubled down on bigger and heavier pony cars — and never looked back. Compare the final Firebird shown below with the first- and second-generation models pictured earlier in this post. Here we have the automotive equivalent of Elvis Presley’s decline. It’s too bad GM did not put the Firebird on a diet before the downward slide became embarrassing.
- Auto editors of Consumer Guide; 2006. Encyclopedia of American Cars. Publications International, Lincolnwood, Ill.
- Classic Car Database; 2018. “Search for specifications.”
- Flammang, James M.; 1992. Standard Catalog of Imported Cars, 1946-1990.First Ed. Krause Publications, Iola, WI.
- Gunnell, John; 2002. Standard Catalog of American Cars, 1946-1975. Revised 4th Ed. Krause Publications, Iola, WI.
- Mueller, Mike; 2010. The Complete Book of Mustang: Every Model Since 1964 1/2.Motorbooks, Minneapolis, MN.
- Old Car Advertisements; 2018. Mercury Capri (1970).
- Old Car Brochures; 2018. Ford Maverick (1970); Plymouth Duster (1970); Pontiac Firebird (1968, 1970).
- Wikipedia; 2018. “Ford Mustang” and “Pontiac Firebird.”