While the concept car shared much of its underpinnings with the two-seater Corvette, the vehicle that would actually go into production in 1958 was a different animal entirely. The Bonneville helped establish the muscle car formula that Pontiac would use to great effect just a few years down the road with the GTO: Build a coupe that could be optioned with minimal frills, stuff the most potent engine your company builds into the engine bay, and offer it at a price that folks can afford.
Development and Specifications
For the 1958 model year, General Motors introduced new bodies and chassis for all of its passenger cars, and this major shake-up of the model portfolio gave Pontiac some room to reposition the brand with a more sporting, youthful vibe. The Bonneville went from being a trim package on the Star Chief the previous year to its own stand-alone model. Positioned as a direct response to Chrysler’s letter-series Chrysler 300 and the DeSoto Golden Adventurer – two Mopar models which were built on a similar concept of placing high performance near the top of the list of priorities – the Bonneville scored the high-performance powerplants of the Star Chief, but it rode on the shorter, 122-inch wheelbase of the Chieftan. While the Chieftan wasn’t exactly svelte, this shorter wheelbase provided a tangible performance advantage over the larger Star Chief chassis.
Because of the fuel-injection system’s high price tag and reputation for temperamental behavior, most Bonneville buyers opted for the trio of two-barrel carburetors offered in the Tri-Power setup, which dropped the horsepower to an even 300 but offered better tunability and a more attractive bottom line.
Although a column-shifted, three-speed manual was the standard gearbox on the Bonneville, few buyers settled for it. Most instead, sprung the extra coin to get GM’s four-speed, Strato-Flight Hydra-Matic automatic, which featured a low 3.97:1 first-gear ratio for the better pull from a standstill. Also giving the big Bonneville some extra punch out of the hole was the availability of the Safe-T-Track limited-slip differential, which debuted in 1958 as well.
Two body styles were offered for 1958 – Sport Coupe and Convertible. Hemmings reports that Pontiac would end up selling 12,240 Bonnevilles in total that year, with 9,144 customers opting for the coupe, while the remaining 3096 buyers chose the drop top.
The Strategy ChangesWith the debut of the second-generation Bonneville in 1959, the model lineup grew to five distinct configurations – coupe, convertible, four-door sedan, four-door hard top, and a wagon. The car’s appearance was a dramatic departure from its predecessor, not only due to a deliberate move away from the rocket-inspired aesthetic of the 1950s toward a more streamlined look that would typify early 1960s vehicle design, but also because of Pontiac engineer’s decision to push the wheels further out toward the fenders to create what would become known as the Pontiac Wide Track design.
By the early 1970s, the model’s connection to high performance was largely in name only, as Pontiac’s focus for the Bonneville became more specifically aimed at personal luxury.
Ultimately, it’s the first-year cars that would endure in the hearts and minds of performance enthusiasts. Due to the car’s significance and scarcity, the 1958 Bonneville is now a highly-sought-after commodity in the collector car market. Well sorted examples can usually be had for around $50,000, though some Bonnevilles have commanded sums well into six-figure territory at auction.
Article courtesy of Street Muscle Magazine, written by Bradley Iger.