The Pontiac GTO was an automobile built by Pontiac from 1964 to 1974, and by General Motors Holden in Australia from 2003 to 2006. It is often considered the first true muscle car. From 1964 until 1973.5, it was closely related to the Pontiac Tempest, but for its final year it was based on the Pontiac Ventura. The 21st century GTO is essentially a left hand drive Holden Monaro, itself a coupe variant of the Holden Commodore.
Origins
The GTO was the brainchild of Pontiac engineer Russell Gee, an engine specialist, and Pontiac chief engineer John De Lorean. Shane Wiser was the first to think of the idea of the GTO. 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. Jim 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 in³ (6.5 L) Pontiac V8 engine from the full-sized Pontiac Catalina and Bonneville in place of the standard 326 in³ (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 drew protest from 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 in³ (5.4 L). Since the GTO was an option package and 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.
Second generation
1968
GM redesigned its A-body line for 1968, with more curvaceous, "bustleback" fastback styling. The previous 115 inch (292 cm) wheelbase was shortened to 112 inches (284 cm) for all two-door models. Overall length was reduced 5.9 inches (150 mm) and height dropped half an inch (12 mm), but overall weight was up about 75 pounds (34 kg). Pontiac abandoned the familiar stacked headlights for hidden headlights behind the split grille (actually a US$52.66 option, but seen on many GTOs). The signature hood scoop was replaced by dual scoops on either side of a prominent hood bulge extending from the protruding nose.
A unique feature was the body-color Endura front bumper. It was designed to absorb impact without permanent deformation at low speeds. Pontiac touted this feature heavily in advertising, showing hammering at the bumper to no discernable effect. Though a rare option, a GTO could be ordered with "Endura Delete", in which case the Endura bumper would be replaced by a chrome front bumper and grille setup from the Pontiac LeMans. This model year further emphasized the curvacious "coke bottle" styling, as viewed from the side.
Powertrain options remained substantially the same as in 1967, but the standard GTO engine rose to 350 hp (261 kW) @ 5,000 rpm. At mid-year, a new Ram Air package became available with freer-breathing cylinder heads, round port exhaust and the 744 cam and 3.90:1 rear differential. Horsepower rating was not changed, although actual output was likely somewhat higher, especially with open exhausts. Another carry-over from 1967 was the 4-piston caliper disc brake option. While most 1968 models had drum brakes all around, this rare option provided greater stopping power and could be found on other GM A-Body vehicles of the same period. 1968 was also the last year the GTOs offered separate vent, or "wing", windows—and the only year for crank-operated vent windows.
Another feature was concealed windshield wipers, hidden below the rear edge of the hood. They presented a cleaner appearance and were another Pontiac first for the industry. Another popular option, actually introduced during the 1967 model year, was a hood-mounted tachometer, located in front of the windshield and lighted for visibility at night. An in-dash tachometer was also available, but the hood tachometer became something of a status symbol.
Redline bias-ply tires continued as standard equipment on the 1968 GTO, though they could be replaced by whitewall tires at no extra cost. A new option was radial tires for improved ride and handling. However, very few were delivered with the radial tires because of manufacturing problems encountered by supplier B.F. Goodrich. The radial tire option was discontinued after 1968. Pontiac did not offer radial tires as a factory option on the GTO again until the 1974 model.
Hot Rod tested a four-speed standard GTO and obtained a quarter mile reading of 14.7 seconds at 97 mph (156 km/h) in pure stock form. Motor Trend clocked a four-speed Ram Air with 4.33 rear differential at 14.45 seconds @ 98.2 mph (158.0 km/h) and a standard GTO with Turbo-Hydramatic and 3.23 gears at 15.93 seconds @ 88.3 mph (142.1 km/h). Testers were split about handling, with Hot Rod calling it "the best-balanced car [Pontiac] ever built," but Car Life chiding its excessive nose heaviness, understeer, and inadequate damping.
Now facing serious competition both within GM and from Ford, Dodge, and Plymouth—particularly the low-cost Plymouth Road Runner—the GTO won Motor Trend's Car of the Year award, and sales remained strong at 87,684 (which was the second-best sales year for the GTO).
1969
The 1969 model did not have the vent windows, had a slight grille and taillight revision, moved the ignition key from the dashboard to the steering column, and the gauge faces changed from steel blue to black. In addition, the rear quarter-panel mounted side marker lamps changed from a red lens shaped like the Pontiac "V" crest to one shaped like the broad GTO badge.
The previous economy engine and standard 350 hp 400 in³ V8 remained, but the 360 hp engine was dropped in favor of a pair of new Ram Air engines. The 400 in³ Ram Air III was rated at 366 hp (273 kW) @ 5,100 rpm, while the top option was the 370 hp (276 kW) Ram Air IV, which featured special header-like high-flow exhaust manifolds, high-flow cylinder heads, a specific high-rise aluminum intake manifold, larger Rochester QuadraJet four-barrel carburetor, high-lift/long-duration camshaft, forged steel crankshaft plus various internal components capable of withstanding higher engine speeds and power output. Unlike the big-block Chevy and Hemi motors, the Ram Air IV utilized hydraulic lifters. As a result, it did not overheat in traffic, nor did it foul spark plugs, which set it apart from the large-displacement performance engines seen in other muscle cars.
By this time, the gross power ratings of both Ram Air engines were highly suspect, bearing less relationship to developed horsepower and more to an internal GM policy limiting all cars except the Corvette to no more than one advertised horsepower per ten pounds of curb weight. The higher-revving Ram Air IV's advertised power peak was actually listed at 5,000 rpm—100 rpm lower than the less-powerful Ram Air III. 1969 was also the year that the Ram Air V was introduced. It was a special 400 block with newly designed high compression tunnel port heads and a special high rise intake manifold. A GTO so equipped could go 0-60 mph in 5.2 seconds, and the quarter-mile time was 11.5 seconds at 123 mph (198 km/h).
The significant event of 1969 was the launch of a new model called 'The Judge'. The Judge name came from a comedy routine, "Here Comes the Judge", used repeatedly on the "Rowan & Martin's Laugh-In TV" show. Advertisements used slogans like "All rise for The Judge" and "The Judge can be bought." As originally conceived, the Judge was to be a low-cost GTO, stripped of some gimmicks to make it competitive with the Plymouth Road Runner. During its development, however, it was decided to make it the ultimate in street performance and image. The resulting package ended up being US$337.02 more expensive than a standard GTO, and included the Ram Air III engine, styled wheels, Hurst shifter (with a unique T-shaped handle), wider tires, various decals, and a rear spoiler. Pontiac claimed that the spoiler had some functional effect at higher speeds, producing a small but measurable down force, but it was of little value at legal speeds except for style. The Judge was initially offered only in "Carousel Red," but late in the model year a variety of other colors became available.
The GTO was surpassed in sales both by the Chevrolet Chevelle SS396 and the Road Runner, but 72,287 were sold during the 1969 model year, with 6,833 of them being The Judge.
1970
The Tempest line received another facelift for the 1970 model year. Hidden headlights were deleted in favor of four exposed round headlamps outboard of narrower grille openings. The nose retained the protruding vertical prow theme, although it was less prominent. While the standard Tempest and LeMans had chrome grilles, the GTO retained the Endura urethane cover around the headlamps and grille.
The suspension was upgraded with the addition of a rear anti-roll bar, essentially the same bar as used on the Oldsmobile 442 and Buick Gran Sport. The front anti-roll bar was slightly stiffer. The result was a useful reduction in body lean in turns and a modest reduction of understeer.
Another handling-related improvement was optional variable-ratio power steering. Rather than a fixed ratio of 17.5:1, requiring four turns lock-to-lock, the new system varied its ratio from 14.6:1 to 18.9:1, needing 3.5 turns lock-to-lock. Turning diameter was reduced from 40.9 feet (12.5 m) to 37.4 feet (11.4 m).
The base engine was unchanged for 1970, but the low-compression economy engine was deleted and the Ram Air III and Ram Air IV remained available, although the latter was now a special-order option.
A new option was Pontiac's 455 engine, available now that GM had rescinded its earlier ban on intermediates with engines larger than 400. The 455, a long-stroke engine taken from the full-size Pontiac Bonneville line, was only moderately stronger than the base 400 and actually less powerful than the Ram Air III. The 455 was rated at 360 hp (268 kW) @ 4,300 rpm. Its advantage was torque: 500 ft-lbf (677 N-m) @ 2,700 rpm. A functional Ram Air scoop was available, but even so equipped, a stock 455 was less powerful than the Ram Air III. Car and Driver tested a heavily optioned 455, with a four-speed transmission and 3.31 axle and recorded a quarter mile time of 15.0 seconds with a trap speed of 96.5 mph (155.3 km/h). Car Life's Turbo-Hydramatic 455, with a 3.35 rear differential, clocked 14.76 seconds at 95.94 mph (154.40 km/h), with identical 6.6 second 0-60 mph acceleration. Both were about 3 mph (5 km/h) slower than a Ram Air III 400 four-speed, although considerably less temperamental: the Ram Air engine idled roughly and was difficult to drive at low speeds. The smaller displacement engine recorded less than 9 miles per gallon of gasoline (26.1 L/100 km), compared to 10 to 11 miles per gallon (23.5 to 21.4 L/100 km) for the 455.
A new and short-lived option for 1970 was the Vacuum Operated Exhaust (VOE), which was cable activated via an underdash lever marked "EXHAUST." The VOE was designed to reduce exhaust backpressure to increase horsepower and performance, but it also substantially increased exhaust noise. The VOE option was offered from November 1969 to January 1970. Pontiac management was ordered to cancel the VOE option by GM's upper management following a TV commercial for the GTO that aired during Super Bowl IV on CBS January 11, 1970. In that commercial, entitled "The Humbler," which was broadcast only that one time, a young man pulled up in a new GTO to a drive-in restaurant with dramatic music and exhaust noise in the background, pulling the "EXHAUST" button to activate the VOE and then left the drive-in to do some street racing. That particular commercial was also cancelled by order of GM management.
The Judge remained available as a separate model. The Judge came standard with the Ram Air III, while the Ram Air IV was optional. Though the 455 in³ was available as an option on the standard GTO throughout the entire model year, the 455 was not offered on The Judge until late in the year. "Orbit Orange" became the new standard color for the '70 Judge, but any GTO color was available on The Judge. Striping was relocated to the upper wheelwell brows.
An Orbit Orange 1970 GTO Judge with the 455 engine and Turbo Hydra-Matic transmission was one of the featured cars in the movie "Two-Lane Blacktop", which depicted a cross-country race between the new GTO and a 1955 Chevrolet Bel Air.
The new styling did little to help declining sales, which were now being hit by sagging buyer interest in all musclecars and by the punitive surcharges levied by automobile insurance companies, which sometimes resulted in insurance payments higher than car payments for some drivers. Sales were down to 40,149, of which 3,797 were The Judge. The GTO remained the third best-selling intermediate musclecar, outsold by the Chevrolet Chevelle SS 396/454 and Plymouth Road Runner.
1971
The 1971 GTO had another modest facelift, this time with wire-mesh grilles, horizontal bumper bars on either side of the grille opening, more closely spaced headlamps, and a new hood with the dual scoops relocated to the leading edge, not far above the grille. Overall length grew slightly to 203.3 inches (516 cm).
A new corporate edict, aimed at preparing GM for no-lead gasoline, forced a cross-the-board reduction in compression ratios. The Ram Air engines did not return for 1971. The standard GTO engine was still the 400 in³ V8, but now with 8.2:1 compression. Power was rated at 300 hp (223 kW) @ 4,800 rpm and torque at 400 ft-lbf (542 N-m) @ 3,600 rpm. An engine option was the 455 in³ V8 with four-barrel carburetor, 8.4 to 1 compression ratio and 325 hp (242 kW), only available with the automatic transmission. The top GTO engine for 1971 was the new 455 HO with 8.4 compression, rated at 335 hp @ 4,800 rpm and 480 ft-lbf (650 N-m) @ 3,600 rpm.
Motor Trend tested a 1971 GTO with the 455, four-speed transmission, and 3.90 axle, and obtained a 0-60 mph time of 6.1 seconds and a quarter mile acceleration of 13.4 seconds at 102 mph (164 km/h).
The Judge returned for a final year, now with the 455 HO as standard equipment. Only 374 were sold before The Judge was discontinued in February 1971, including 17 convertibles—today the rarest of all GTOs.
Only 10,532 GTOs were sold were sold in 1971.
1972
In 1972, the GTO reverted from a separate model line to a US$353.88 option package for the LeMans and LeMans Sport coupes. On the base LeMans line, the GTO package could be had with either the low-priced pillared coupe or hardtop coupe. Both models came standard with cloth and vinyl or all-vinyl bench seats and rubber floor mats on the pillared coupe and carpeting on the hardtop, creating a lower-priced GTO. The LeMans Sport, offered only as a hardtop coupe, came with Strato bucket seats upholstered in vinyl, along with carpeting on floor and lower door panels, vinyl door-pull straps, custom pedal trim and cushioned steering wheel, much like GTOs of previous years. Other optional equipment was similar to 1971 and earlier models. Planned for 1972 as a GTO option was the ducktail rear spoiler from the Pontiac Firebird, but after a few cars were built with that option, it was cancelled. Rally II and honeycomb wheels were optional on all GTOs, with the honeycombs now featuring red Pontiac arrowhead emblems on the center caps, while the Rally IIs continued with the same caps as before, with the letters "PMD" (for Pontiac Motor Division).
Horsepower, now rated in SAE net terms, was down further, to 250 hp (186 kW) @ 4,400 rpm and 325 ft-lbf (440 N-m) @ 3,200 rpm torque for the base 400 engine. The optional 455 had the same rated horsepower (although at a peak of 3,600 rpm), but substantially more torque. Most of the drop was attributable to the new rating system (which now reflected an engine in as-installed condition with mufflers, accessories, and standard intake). The engines were relatively little changed from 1971.
The teaser renderings and photos of the faux-Pontiac reveal a bespoke front end with a split grille and a revised hood with air scoops, while at the back we find new tail lamp and bumper designs as well as a restyled trunk sporting a prominent wing. The characteristic profile side stripes, quad tail pipes and the newly styled alloy wheel options round off the exterior changes. There’s no word yet if there will be any kind of upgrades to the interior and the mechanical hardware of the Camaro. 
