1965 Buick Riviera Gran Sport: Two Four-Barrels for the Gentleman's Express

In 1965 Buick hung the same two words on two very different cars. On the intermediate Skylark, the new Gran Sport option was built around the 401-cubic-inch V8, which Buick called a 400 because that was the largest engine General Motors then allowed in its intermediate bodies. The Riviera had no such ceiling. Its Gran Sport took the biggest engine Buick built, the 425 with two four-barrel carburetors, and put it in a car that already cost more than most performance buyers would pay. One badge covered a young man's hot rod and a banker's express.^1,2,3

The Riviera needed a new argument. Its first year had been capped at 40,000 cars, and the count slid afterward: 37,658 for 1964 according to the Riviera Owners Association and Ate Up With Motor, 37,958 according to Wikipedia's table, and 34,586 for 1965. Ate Up With Motor explains the slide as an awkward niche. The Riviera was, in its words, 'much too expensive for the performance-minded young buyer,' yet it lacked the sheer ostentation that pulled customers toward the Thunderbird or a Cadillac. A performance package aimed at buyers who could afford the car, rather than at the drag strip crowd, was one way to give it an edge.^4,3,2

The hardware already existed. For 1964 Buick had made the 340-horsepower 425 standard in the Riviera and added a 360-horsepower Super Wildcat version with two Carter carburetors, and it replaced the old twin-turbine automatic with the three-speed Super Turbine 400, Buick's name for the Turbo Hydra-Matic. The Owners Association counts 2,122 Super Wildcat cars among the 1964 Rivieras. What 1965 changed was the packaging. The 325-horsepower 401 returned as the standard engine, the single four-barrel 425 stayed on the option list, and the dual-quad engine became the heart of a named package.^2,3,4

Wikipedia describes the 1965 Gran Sport as the Super Wildcat, rated at 360 gross horsepower with two 625-cfm Carter four-barrels, plus a 3.42 axle and dual exhaust pipes enlarged from 2.0 to 2.25 inches inside diameter with fewer bends to cut back pressure. Ate Up With Motor prices the Super Wildcat at $188 and pairs the 3.42 gears with a Positraction limited-slip differential. The handling was sold separately. A $37.63 ride and handling package brought a quicker steering ratio, stiffer springs and firmer shocks, so a Gran Sport buyer who wanted the chassis to match the engine had one more box to check.^2,3

The body gained the feature Nickles had drawn in the first place. Concealed headlamps had been part of the XP-715 design but were deleted for cost and technical reasons in 1963 and 1964; for 1965 the lamps were stacked vertically behind clamshell doors in the leading edges of the fenders, driven, Ate Up With Motor notes, by electric motors rather than vacuum. Wikipedia adds that the non-functional side scoops disappeared, the taillights moved into the rear bumper, a black vinyl roof became available and a tilt steering wheel became standard. The Gran Sport looked like any other 1965 Riviera, apart from its badges.^3,2

The production figures reconcile unusually neatly. The Riviera Owners Association lists 34,586 Rivieras for 1965 and 3,354 with the Gran Sport option, about 9.7 percent, which matches Ate Up With Motor's 'about 10%.' By engine, the same table counts 28,467 cars with the 401, about 82 percent; 2,311 with the single four-barrel 425; and 3,808 with the dual-quad Super Wildcat, about 11 percent. Its note says only 454 of the dual-quad engines went into cars without the GS option, and 3,808 less 454 is exactly 3,354. The engine rows sum to the 34,586 total, which Wikipedia's Standard Catalog lineage also gives.^4,3,2

Set beside the Skylark, the numbers describe two different markets. Over-Drive's compiled mid-size table counts 15,780 Skylark Gran Sports for 1965, more than four times the Riviera figure, and Car Life priced the Skylark package at $200.53 in its May 1965 test. That Skylark, an automatic with air conditioning, reached 60 mph in 7.4 seconds and ran the quarter mile in 15.3 seconds at 88 mph. Those figures belong to that car alone. The Riviera Gran Sport's buyers were spending luxury-car money first and performance money second, and there were roughly 3,400 of them.^5,6,4

The distance Buick had travelled since launch shows in the hardware. Motor Trend's 1963 test Riviera carried the same 325-horsepower 401 that returned as the 1965 base engine, a 3.23 axle and the twin-turbine automatic; it reached 60 mph in 8.1 seconds and ran the quarter mile in 16.01 seconds at 85.71 mph, and its as-tested price was $5,158.61. The 1965 Gran Sport added 35 rated horsepower, a second four-barrel, the three-speed Super Turbine 400 and the shorter 3.42 gears. The hardware gap is plain on paper. The stopwatch gap is not documented by a period test of the 1965 car, and the 1963 figures belong only to the car Motor Trend drove.^7,2

What the Riviera Gran Sport could do is reported in general terms by Ate Up With Motor, which says a Super Wildcat car was capable of about 7 seconds from rest to 60 mph and a top speed of nearly 130 mph. It does not tie those figures to a named test, so they stand as characterization rather than measurement. The same history is candid about the costs: an exaggerated sensitivity to crosswinds and fuel consumption that could fall below 10 mpg when the car was driven hard. Reviewers, it says, were predictably ecstatic. Buyers, as the 9.7 percent take rate shows, were more measured.^3,4

The Gran Sport idea outlived the first-generation body. The Riviera Owners Association records a Gran Sport option on the new 1966 Riviera, 5,718 of 45,348 cars, and in every year of that table through 1975, when 3,101 cars carried the GS handling option. The Skylark branch grew into the GS 400 and later GSX. For the Riviera, 1965 established the formula that lasted: take the most refined body Buick sold, give it the biggest engine and a shorter axle ratio, and offer it to the few buyers who wanted their luxury coupe to hurry.^4,1