For 1974, the General Motors Colonnade styling theme was applied to the Riviera, Buick’s personal luxury cruiser.

In 1974 the Colonnade styling theme came to General Motors, and to Buick’s personal luxury flagship as well. Under the skin, this new Riviera was much the same as the previous ’71-’73 boattail coupes: same rugged perimeter frame with a generous 122-inch wheelbase, coil springs at all four wheels, and conventional front engine/rear-drive layout. In that regard, the RIviera differed from its GM E-body companions, the front-drive Olds Toronado and Cadillac Eldorado.

However, the Riviera’s new exterior fully embraced the GM Colonnade theme, with a formal greenhouse, thick B-pillars and fixed rear quarter windows. The rear deck and quarter panels were squared up to complement the more abrupt roofline, and the front end was revised as well to accommodate the government-mandated five-mph bumper.

Compared to the dramatic boattail, this new Riviera was more subdued, less polarizing. Arguably, this Riviera offered the least distinctive styling since the 1963 introduction. As designer Wayne Kady would note years later, the exterior was a compromise to satisfy  a number of corporate concerns, including cost, component sharing, and federal regulations.

As any Riviera should, the fourth-generation car offered a catalog full of exterior color and interior trim possibilities: benches, buckets, cloth, vinyl, and leather. Standard features included tilt steering, lighted ashtrays, and a digital clock with mechanical numerals. While the usual luxury appointments like power windows and air conditioning were actually extra-cost options, the take rates were very high: 97 and 99 percent, respectively.

All ’74-’76 Rivieras were powered by a 455 cubic-inch V8 backed up by a Turbo-Hydratic 400 transmission. In ’74, the standard V8 was rated at 230 hp, but a Stage I engine with 245 hp was available. Along with the big-port cylinder heads, the Stage I package ($139) included a limited-slip differential and badges. But for 1975, the Stage I was dropped and the standard V8 was downrated to 205 hp as the catalytic converter was adopted. There was a GS option in ’74-’75, a $108 handling package with a rear stabilizer bar, radial-tuned suspension, and emblems. At 4,700+ lbs, the Riviera was a highway cruiser, not a quarter-mile racer.

Exterior changes were minimal over the ’74-’76 product cycle—mainly, a revised front fascia and grille in 1975. But while the more restrained styling compared to the boattail was less polarizing, it wasn’t more popular. Sales dropped significantly, from 34,000 cars in 1973 to barely 20,000 in ’74. Volume fell again in ’75 to just 17,000—the Riviera’s worst year to date—then recovered slightly to 20,000 in ’76. For 1977, the Colonnade coupe was retired to make way for an equally luxurious but much smaller and lighter Riviera, and you can find its story here.