Under the direction of Bunkie Knudsen, Pontiac was rapidly transforming into the youth and performance brand at General Motors. Here are the changes for ’58.

Bonneville Hardtop Coupe 

At Pontiac, the 1958 model year stands alone. The Silver Streak bright-trim era had ended the year before, the Wide Track era was one year in the future, and the exterior styling was a one-year-only design. But more to the point, 1958 is noted as the first year in which Pontiac general manager Semon E. “Bunkie” Knudsen and his team, chief engineer Pete Estes and assistant chief engineer John Z. DeLorean, had real control over the division’s products. And with remarkable speed, they were reinventing the brand.

Bonneville Convertible Indianapolis 500 Pace Car 

For ’58, Pontiac adopted a GM corporate X-frame chassis similar to Chevrolet’s, but with a longer wheelbase—122 inches for the Chieftain, Bonneville, and station wagons, 124 inches for the Super Chief and Star Chief. It was plainly evident that the basic body shell, including the roof and greenhouse, was shared with Chevrolet as well. Still,  Pontiac studio chief Paul W. Gillian, working under the direction of GM styling boss Harley Earl, did a rather masterful job of providing the Pontiac with its own visual identity. The Bonneville featured an elaborate diecast trim piece in its quarter-panel coves that Pontiac never graced with a name, but it was known to consumers as a “guided missile.”

Chieftain Four-Door Sedan

Introduced in mid-1957 as a limited-edition convertible in the Star Chief line, the Bonneville became a stand-alone model in ’58, and now offered in two body styles, Convertible and Hardtop Coupe. From there, the trim levels included the base Chieftain, the mid-range Super Chief, and the traditional flagship of the Pontiac line, the Star Chief. However, this would be the final season for the Chieftain and the Super Chief, as they were dropped for 1959 and the Bonneville became the new top of the Pontiac line.

With an increase in cylinder bore from 3.94 to 4.06 inches, the Pontiac V8 grew from 347 to 370 cubic inches, and was now available in eight different versions for ’58 rated from 240 hp to 330 hp. Two were special-order NASCAR packages, while the standard V8 in the Bonneville, equipped with a four-barrel carb and 10:1 compression ratio, was rated at 285 hp. Optional production V8s included a Tri-Power 3×2 combination offering 300 hp and the 310 hp V8 with Rochester mechanical fuel injection (similar to the Chevrolet system). But at $500 the fuel injection option was a tough sell, since the $94 Tri-Power combination offered essentially the same performance with far less cost and bother. The fuel injection system was dropped at the end of the year.

Star Chief Catalina Hardtop Coupe 

The 1958 model year was a tough one for the Motor City as domestic auto production fell from 6.1 million to 4.3 million due to the nation’s first real postwar recession. The mid-price class was especially hard hit by tight money, as buyers hung onto their cars another year or dropped into the low-priced field. Pontiac sales suffered, too, but not as badly as some other mid-range brands. Knudsen and crew continued on course, building Pontiac into the powerhouse style and performance brand at General Motors for the next decade.