Origins
   
   The GTO was the brainchild of McManus advertising agency executive Jim Wangers, an automotive enthusiast, and Pontiac chief engineer John De Lorean. In early 1963 General Motors management issued an edict banning divisions from involvement in auto racing. At the time Pontiac's advertising and marketing approach was heavily based on performance, and racing was an important component of that strategy. Wangers proposed a way to retain the performance image that the division had cultivated with a new focus on street performance. It involved transforming the upcoming, redesigned Tempest (which was set to revert to a conventional front-engine, front transmission, rear-wheel drive configuration) into a "Super Tempest" with the larger 389 cubic-inch (6.4 L) Pontiac V8 engine from the full-sized Pontiac Catalina and Bonneville in place of the standard 326 cubic-inch (5.3 L) Tempest V8. By promoting the big-engine Tempest as a special, high-performance model, they could appeal to the speed-minded youth market (which had also been recognized by Ford Motor Company's Lee Iacocca, who was at that time preparing the Ford Mustang).
   The name, which was DeLorean's idea, was inspired by the Ferrari 250 GTO, the highly successful race car. It is an acronym for Gran Turismo Omologato, Italian for homologated for racing in the GT class. The name was to draw howls of protest from outraged purists, who considered it close to sacrilege.
   The GTO was technically a violation of GM policy limiting the A-body intermediate line to a maximum engine displacement of 330 cubic-inch (5.4 L). Since the GTO was an option package, not standard equipment, it could be considered to fall into a loophole in the policy. Pontiac General Manager Elliot (Pete) Estes approved the new model, although sales manager Frank Bridge, who did not believe it would find a market, insisted on limiting initial production to no more than 5,000 cars. Had the model been a failure, Estes likely would have been reprimanded. As it turned out, it was a great success.
   
   First generation
   
   1964
   The first Pontiac GTO was an option package for the Tempest Le Mans, available with the two-door sedan, hardtop coupe, and convertible body styles. For $296, it included the 389 in³ V8 (rated at rated at 325 hp @ 4800 RPM) with a single Carter AFB four-barrel carburetor and dual exhausts, chromed valve covers and air cleaner, 7 blade declutching fan, a floor-shifted three-speed manual transmission with Hurst shifter, stiffer springs, larger diameter front sway bar, wider wheels with 7.50 x 14 redline tires, hood scoops, and GTO badges. Optional equipment included a four-speed manual transmission, two-speed automatic transmission, a more powerful "Tri-Power" engine with three two-barrel carburetors (rated at 348 bhp), metallic drum brake brake linings, limited-slip differential, heavy-duty cooling, ride and handling package, and the usual array of power and convenience accessories. With every available option, the GTO cost about $4500 USD and weighed around 3500 lb.
   Most contemporary road tests used the more powerful Tri-Power engine and four-speed. Car Life clocked a GTO so equipped at 0-60 mph (0-97 km/h) in 6.6 seconds, through the standing quarter mile in 14.8 seconds with a trap speed of 99 mph (158 km/h). Like most testers, they criticized the slow steering, particularly without power steering, and inadequate drum brakes, which were identical to those of the normal Tempest. Car and Driver incited storms of controversy when it printed that a GTO that had supposedly been tuned with the "Bobcat" kit offered by Royal Pontiac of Royal Oak, Michigan was clocked at a quarter-mile ET of 12.8 seconds and a trap speed of 112 mph (179 km/h) on racing slicks. Later reports strongly suggest that the C&D GTOs were not equipped with the 389, but with the 421 in³ (6.9 L) Super Duty engine that was optional in full-sized Pontiacs. Since the two engines were difficult to distinguish externally, the subterfuge was not immediately obvious.
   Frank Bridge's gloomy sales forecast proved inaccurate: the GTO package had sold 10,000 units before the beginning of the 1964 calendar year, and total sales were 32,450.
   
   Bobcats
   Throughout the 1960s, Royal Pontiac, a Pontiac car dealer in Royal Oak, Michigan, offered a special tune-up package for Pontiac 389 engines. Many were fitted to GTOs, and the components and instructions could be purchased by mail as well as installed by the dealer. The name "Bobcat" came from the improvised badges created for the modified cars, combining letters from the "Bonneville" and "Catalina" nameplates. Many of the Pontiacs made available for magazine testing were equipped with the Bobcat kit.
   The precise components of the kit varied, but generally included pieces to modify the spark advance of the distributor, limiting spark advance to 34-36° at no more than 3000 RPM (advancing the timing at high RPM for increased power), a thinner head gasket to raise compression to about 11.23:1, a gasket to block the heat riser of the carburetor (keeping it cooler), larger carburetor jets, high-capacity oil pump, and fiberglass shims with lock nuts to hold the hydraulic valve lifters at their maximum point of adjustment, allowing the engine to rev higher without "floating" the valves. Properly installed, the kit could add between 30 and 50 horsepower, although it required high-octane superpremium gasoline of over 100 octane (i.e. Sunoco 260, Chevron Custom Supreme) to avoid spark knock with the higher compression and advanced timing.
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   1965
   The Tempest line, including the GTO, was restyled for the 1965 model year, adding 3.1 in. to overall length while retaining the same wheelbase and interior dimensions. It now sported Pontiac's characteristic vertically stacked quad headlights. Overall weight increased about 100 lb, model for model. Brake lining area increased just under 15%. The dashboard design was improved, and an optional Rally Gauge Cluster ($86.08) added a more legible tachometer and oil pressure gauge.
   The 389 engine got revised cylinder heads with re-cored intake passages, improving breathing. Rated power increased to 335 hp @ 5000 RPM for the base 4-bbl engine; the Tri-Power was rated 360 hp @ 5200 RPM. The Tri-Power engine had slightly less torque than the base engine, 424 lb-ft @ 3600 rpm versus 431 lb-ft @ 3200 rpm. Transmission and axle ratio choices remained the same.
   The restyled GTO had a new simulated hood scoop. A rare, dealer-installed option was a metal underhood pan and gaskets that allowed the scoop to be opened, transforming a cosmetic device into a functional ram air intake. The scoop was low enough that its effectiveness was questionable (it was unlikely to pick up anything but boundary layer air), but it at least admitted cooler, denser air, and allowed more of the engine's formidable roar to escape.
   Car Life tested a 1965 GTO with Tri-Power and what they considered the most desirable options (close-ratio four-speed manual transmission, power steering, metallic brakes, rally wheels, 4.11 limited-slip differential, and Rally Gauge Cluster), with a total sticker price of $3643.79. With two testers and equipment aboard, they recorded 0-60 mph (0-97 km/h) in 5.8 seconds, the standing quarter mile in 14.5 seconds with a trap speed of 100 mph (160 km/h), and an observed top speed of 114 mph (182.4 km/h) at the engine's 6000 RPM redline. Even Motor Trend's four-barrel test car, a heavier convertible handicapped by the two-speed automatic transmission and the lack of a limited-slip differential, ran 0-60 mph in 7 seconds and through the quarter mile in 16.1 seconds at 89 mph (142.4 km/h).
   Major criticisms of the GTO continued to center on its slow steering (ratio of 17.5:1, four turns lock-to-lock) and mediocre brakes. Car Life was satisfied with the metallic brakes on its GTO, but Motor Trend and Road Test found the standard drums with organic linings to be alarmingly inadequate in high-speed driving.
   Sales of the GTO, abetted by a formidable marketing and promotional campaign that included songs and various merchandise, more than doubled to 75,342. It was already spawning many imitators, both within other GM divisions and at its competitors.
   
   1966
   Pontiac's intermediate line was restyled again for 1966, gaining more curvaceous styling with kicked-up rear fender lines for a "Coke-bottle" look, and a slightly "tunneled" backlight. Overall length grew only fractionally, to 206.4 in (5243 mm), still on a 115 in (2921 mm) wheelbase, while width expanded to 74.4 in (1890 mm). Rear track increased one inch (25 mm). Overall weight remained about the same. The GTO became a separate model series, rather than an option package, with unique grille and tail lights, available as a pillared two-door sedan, a hardtop, or a convertible. Also an automotive industry first, plastic front grilles replaced the pot metal and aluminum versions seen on earlier years. New Strato bucket seats were introduced with higher and thinner seat backs and contoured cushions for added comfort and adjustable headrests were introduced as a new option. The instrument panel was redesigned and more integrated than in previous years with the ignition switch moved from the far left of the dash to the right of the steering wheel. Four pod instruments continued and the GTO's dash was now highlighted by walnut veneer trim.
   A new rare engine option was offered, the XS engine consisted of a factory Ram Air set up with a new 744 high lift cam.
   Sales continued to increase, to 96,946. Although Pontiac had strenuously promoted the GTO in advertising as the "GTO Tiger," it had become known in the youth market as the "Goat." Pontiac management attempted to make use of the new nickname in advertising, but were vetoed by upper management, which was dismayed by its irreverent tone.
   
   1967
   Styling remained essentially unchanged for 1967, but the GTO saw several significant mechanical changes.
   A corporate policy decision banned multiple carburetors for all cars except the Chevrolet Corvette, so the famous Tri-Power engine was cancelled in favor of a new Quadrajet four-barrel carburetor. To compensate, the 389 engine received a slightly wider cylinder bore (4.12 in., 104.7 mm) for a total displacement of 400 in³ (6.5 L). Torque increased slightly, from 431 to 441 lb·ft (584 to 598 N·m) for the base engine, from 424 to 438 lb·ft (575 to 594 N·m) for the optional engine, but power remained the same. Testers found little performance difference, although the distinctive sound and fury of the Tri-Power was missed.
   Two new engines were offered. The first, bizarrely, was an economy engine, also 400 in³, but with a two-barrel carburetor, 8.6:1 compression, and a rating of 265 hp (198 kW) and 397 lb·ft (538 N·m) of torque. Offered only with an automatic, it was coolly received by GTO buyers. The second, offered for a formidable extra cost of $263.30 over the standard high-output engine, was the Ram Air engine. The package, which included a functional hood scoop (much like the previous dealer-installed set-up), featured stiffer valve springs and a longer-duration camshaft. Rated power and torque were unchanged, although the engine was certainly stronger than that of the standard 360 hp (268 kW) GTO. It was available only with 3.90:1 or 4.33:1 differential gearing, and its "hotter" camshaft left it with a notably lumpier idle and less cooperative part-throttle response.
   Emission controls, including an air injector system, were fitted in GTOs sold in California only.
   Two more positive changes were in the area of transmission and brakes. The archaic two-speed automatic gave way to the three-speed Turbo-Hydramatic(TH400), available with any engine. The T-H was further enhanced by the use of Hurst's Dual-Gate shifter, which allowed full manual selection of gears, and was generally considered an equal match for the four-speed in most performance aspects. Meanwhile, the Tempest's inadequate drum brakes could finally be replaced by disc brakes on the front wheels (for $104.79, including power boost), a vast improvement in both braking performance and fade resistance.
   Hot Rod Magazine tested a 1967 Ram Air GTO with Turbo-Hydramatic and 3.90 gearing, and obtained a quarter-mile performance of 14.51 seconds @ 98.79 mph (158.99 km/h) in pure-stock form, rising to 14.11 @ 101.23 mph (162.91 km/h) with accessory drive belts removed, new spark plugs, and a slight modification to the carburetor. Car Life's similar car ran 0-60 mph (0-97 km/h) in 6.1 seconds and the quarter in 14.5 seconds @ 102 mph (163 km/h) with 4.33 gears. They were critical, however, of the Ram Air's finicky behavior and tendency to overheat in traffic, as well as the ease with which a careless driver could exceed the 5600 RPM redline in top gear (which limited the car to a maximum speed of 107 mph (171 km/h) with a 4.33 axle ratio). Nor was it cheap: for performance and appointments very similar to their 1965 Tri-Power, the price was $4422, a 20% increase.
   Nevertheless, GTO sales remained high at 81,722.
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