Pontiac Bonneville in the 1970s wasn't even Pontiac's best. For 1971 it was eclipsed by a fancier offshoot series called Grand Ville, also offering two- and four-door hardtops and snatching the Bonneville's convertible style.
Wheelbase on both lines measured 126 inches (127 for wagons), just an inch under the Buick Electra's, as big as a Pontiac would ever get. Appearance was clean but sadly forgettable. Two-barrel carburetion and lower, 8.2:1 compression gave Pontiac Bonneville just 280 standard horsepower and somewhat milder performance, the four-barrel 455 being reserved for Grand Ville.
After a stand-pat 1972, Pontiac Bonneville returned to its old 124-inch wheelbase for 1973. Model offerings were down to three: four-door sedan and hardtop coupe and sedan. The 400, in two-barrel form, was again standard issue, but with a mere 180 horsepower in newly mandated SAE net measure on 8.0:1 compression.
However, the four-barrel 455 with 215 horsepower net was optionally available (and still base power in Grand Ville). With wagons bumped up to Grand Ville status and increased emphasis on the mid-size Grand Prix and LeMans, series output came to fewer than 47,000 units for the model year.
Volume dropped to 20,560 for the little-changed 1974s, which took on 5-mph rear bumpers to match the previous year's required front ones. The sedan was lost but wagons regained the following year, when prices were bumped $500, in part because of the government's newly mandated catalytic converter.
Thanks to the model shuffling and an upswing in big-car demand following the 1973-1974 oil embargo, Pontiac Bonneville's 1975 volume improved to near 28,000 units. But Pontiac as a whole was foundering, with a confusing array of models, indifferent workmanship, and an image blurred by too much sharing among General Motors' five makes.
The division's only real winners by now were the personal-luxury Grand Prix and the Firebird Trans Am, the latter not even that strongly associated with Pontiac in the public mind. Grand Ville, which perhaps understandably had never really caught on, was retired at year's end, thus returning Bonneville to the top of a little-changed big-Pontiac line for 1976.
The first wave of General Motors' historic downsizing program brought a trimmer and far more successful Pontiac Bonneville. Measuring 115.9 inches between wheel centers, the all-new 1977 was a tad shorter and a few pounds lighter than the mid-size LeMans, and more than a foot shorter overall than its immediate predecessor.
Yet like its divisional B- and C-body stablemates, space utilization was so effective that hip and shoulder room suffered but fractionally, and head, leg, and trunk room were actually improved. Weight was also down -- by a significant 740 pounds.
This in turn allowed use of a smaller V-8 with little sacrifice in performance. Sized at 301 cubic inches, it produced 135 horsepower net with two-barrel carb and 8.2:1 compression. The only power option initially offered was Oldsmobile's four-barrel 403 with 185 net horsepower.
But history has a way of repeating itself in the car business, and the 1977 Bonneville proves it. Like the 1954 Chieftain Special, Pontiac's smaller big cars were overshadowed by Chevrolet cousins on one side, the B-body Caprice/Impala, and an Oldsmobile on the other, the equally popular Delta 88. Sales were thus disappointing (but changes few) through 1980.
Continue to the next page to follow the Pontiac Bonneville story into the 1980s.
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