The Gran Sport name has been used on several high-performance cars built by General Motors for its Buick brand since 1965. In the GM brands hierarchy, Buick was surpassed in luxury and comfort appointments only by Cadillac, which did not produce performance models. As a result, the Buick GS series were the most opulently equipped GM sport models of their era.

The Gran Sport performance enhancements on all Buick products during this era sought to affirm Buick's tradition of producing powerful and comfortable products going back to the 1930s when all Buicks of the time were upgraded to the Buick Fireball Straight Eight, then installed the Roadmaster engine in the shortest model Special and introduced the Century, known as "the banker's hot rod" with a three speed synchromesh manual transmission. The Gran Sport sought to identify cars that were fun to drive with a luxury approach.

Buick Gran Sport

Skylark based Gran Sports

The 1965 Skylark Gran Sport was the intermediate Buick Skylark with the Gran Sport option added. Although a V8 was already offered in the Skylark, the Gran Sport had the largest engine permitted by GM - a Buick V8 (called a 400 by Buick because that was the maximum engine size allowed in intermediate body cars). This engine produced 325 hp (242 kW) and 445 lb·ft (603 Nm) and was known as the "nailhead" engine. Buick sold more than 15,000 Skylarks with the Gran Sport option that first year, and almost as many the next. It was renamed the GS 400 in 1967, and the Gran Sport became its own model in (about) that same year along with a new "400" engine quite different from the famously reliable but becoming-obsolete nailhead engine design that was first introduced in 1953. Sales fell somewhat in the face of increasingly higher-performance and more popular muscle cars from other marques, including corporate stablemates Pontiac GTO, Chevrolet Chevelle SS and Oldsmobile 442, when compared to those from the more conservative and luxurious Buick. Buick, however, stepped it up a notch when introducing the Stage 1 option in 1969. This limited production (less than 1,500 cars in 1969) version delivered 340 hp (253 kW) and 440 lb·ft (597 Nm).

Buick Gran Sport

The name Gran Sport replaced the GS moniker with the 1973 Gran Sport, and was again revived in the late eighties on the FWD Skylark model with various performance options added.

Buick Gran Sport

GS California

Buick touted the California as "The Distinctive Personal Car for Americana on the GO", using the Skylark platform. The merchandising creation of the West Coast's Mickey Garrett, the California GS became one of Buick's entries into what is now often known as a junior musclecar. The intent of these autos were to provide the visual impact of the era's supercars with the low maintenance and price of a more economical car, while maintaining reasonable performance levels. When reviewed with these thoughts in mind the California GS delivered quite nicely. They were fitted with the small block GS drivetrain and the exterior received the full treatment including vinyl top, chrome moulding package, GS emblems, and special California scripts. This marketing approach was also used in Colorado, using the "Colorado" name instead of "California".

1967 was the maiden year for the California GS. It was available in California only and was not advertised nationally by Buick. Built on the thin-pillar coupe chassis it came equipped with the 340 ci/260 hp engine and Super Turbine 300 transmission. Bench seats were standard and accessories were kept to a minimum to help keep the price down. Car Life tested one in their June issue and ran the 1/4 in 16.7 seconds at 81 mph, they also recorded a top speed of 105 mph. The article contains a lengthy description of the car and how it performed during testing, it is a must read for anyone interested in learning more about the '67 California GS.