The
ultimate GM full size in Oldsmobile guise was outsold by its Buick equivalent
since 1967, though B-body Delta 88 would soon outsell its Buick
equivalents. These GM models were the last with the regular body styles
of sedan, hardtop, convertible and wagon. The Delta 88 would no longer
reach the 250,000-mark attained for 1969.
The
Delta 88 Royale Hardtop Coupe had its formal roof with small back window only
in 1971, after which it adopted the regular roof of the Delta 88 Custom Hardtop
Coupe, due to slow sales. By 1974, the
roof of the Delta 88 Coupe received a large opera window, and the Ninety-Eight
was given a hood ornament. The following year, the Ninety-Eight 2-door
would lose its traditional hardtop roof, and the Delta 88 and Ninety-Eight
4-door hardtops received an opera window in the C-pillar. Oldsmobile
announced that it was the last year for the full size (Delta 88) convertible,
resulting in nearly doubling its sales.
The Delta 88 sedan was given a revised roof and larger rear side
windows. Radial tires became standard equipment. The Ninety-Eight
received rectangular headlights, followed by the Delta 88 and Custom
Cruiser in 1976, with the Royale getting a hood ornament.
Oldsmobiles
now rode on regular fuel. The 3-speed manual transmission was only
available until Spring 1971. Power front disc brakes and variable-ratio
power steering were standard from the start. In December 1973, an airbag
became optional on selected models, but not for too long. From 1974, only
4-barrel engines were available to compensate the lost power because of the
upcoming catalytic converter by 1975, but the Canadians could opt for a 455 cid
2-barrel. A 400 cid Pontiac engine was a
credit option for the Custom Cruiser and Ninety-Eight in 1975.
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