Both TV and printed ads for Firsts Gens included the terms "widetrack" and "widetracking". Given that the GM F-bodies shared the same frame and similar body panels, besides a marketing campaign, what was that? I suppose the multiple GM A-bodies then would have the same question.
The Pontiac studio explored a variety of design concepts for the 1959 model, some of them quite grotesque. Fortunately, the completed design was the most restrained and tasteful of GM’s 1959 cars. Like the 1959 Chevrolet, the 1959 Pontiac now shared the larger B-body used by Buick and Oldsmobile, which was longer and nearly 5 inches (127 mm) wider than the 1958 A-body. Despite that similarity, the Pontiac looked distinctly different, sporting a new split grille treatment and an unusually wide tread width.
The wider track emerged from the designers’ recognition that while the ’59 B-body was noticeably wider than its predecessors, the tread width of GM’s chassis had remained more or less constant since the end of the war. In late 1956 or early 1957, Chuck Jordan’s advanced styling studio had experimentally moved the wheels farther apart without altering the wheelhouses themselves. Knudsen, Estes, and DeLorean saw Jordan’s model on one of their periodic visits and Knudsen took a fancy to it, feeling it gave the car a more athletic stance.
Pontiac’s ad agency, MacManus, John & Adams, latched onto that feature as an advertising hook and copywriter Milt Colson coined the term “Wide Track.†Although Knudsen didn’t particularly like it, considering it hokey, the slogan became very successful. It was not entirely hyperbole; the 1959 Pontiac did indeed have a greater tread width with than any contemporary GM car, fully 3 inches (76 mm) wider than that of the 1959 Cadillac. The wider track did provide some handling benefits, although it was not as miraculous as the ads implied. Lateral weight transfer in turns is a function of tread width and the height of the center of gravity, so the wider track provided more level cornering without stiffer springs or anti-roll bars.
The First Gen Firebirds are indeed lower and wider than their Camaro counterparts. The Pontiac 8.2 rear end is 1†wider than the 8.2 Chevy.
68 Firebird coupe: Length : 188.8 Width : 73.6 Height : 50.2 in Wheelbase : 108.0 in Front Track : 60.0 in Rear Track : 60.0 in
68 Camaro coupe: Length : 185.0 in Width : 72.3 in Height : 50.9 in Wheelbase : 106.0 in Front Track : 59.0 in Rear Track : 58.0 in