1978 was the 75th anniversary of Buick, and the Riviera celebrated the birthday with the $586 LXXV option. It sported a special black and silver paint scheme with special anniversary insignia. The interior was appointed in gray leather, with brushed silver trim on the dash and matching steering wheel. Only 2,899 of the LXXV model were produced, though Buick had initially intended to make only 1,000 the popularity of the package demanded a longer production run. Few changes were made in 1978. revisions of the grill and tail lamps were hardly noticeable. A new electronic height control system was optional.

All engine options remained the same. There was a slight reduction in weight, with 83 pounds being lost, reducing the car to about 3,700 pounds dry.

Air conditioning, a $581 option, had reached a new high, with 99.8% of the 1978 models receiving the system. The $95 cruise control option amounted to being installed in 91.4% of the Riviera’s. 90.8% included a vinyl roof, 64.6% included a stereo tape deck, while 7.1% featured a factory in-dash CB radio. The price increased by $1,666. Sales dropped from the 1977 model year to 20,353 units, in the Riviera's 15th year of production.

The interior was appointed in gray leather, with brushed silver trim on the dash and matching steering wheel.

Though changes may not have been dramatic, the 1978 model remained one of the most elegant of its time. It also was the last year for the rear-wheel-drive chassis to be used. The comfort and ride that was obtained with this model has been said to be the best of any Riviera. The 50/50 velour seats were comfortable, and the interior appointments, such as dual front armrests, cut pile carpeting, and padded steering wheel made any trip a pleasant one.

Year

Total Production

 

 

Engine Size

HP

Carbs

Produced

1978

Standard:

 

Year

Curb Weight

Wheelbase

&nbsp

Track

Length

&nbsp

Width

&nbsp

Height

&nbsp

Tire

Front

Rear

Size

1978

3900

115.9

61.8

60.7

218.2

74.4

55.0

GR78x15