The Pontiac GTO, in all respects a muscle car, debuted in 1964 and continued until 1974. John Zachary DeLorean, best known for the Delorean automobiles, was the individual who forced the development of the legendary GTO. The vehicle was very successful because it was able to capitalize on a segment of the market that had not been fully realized. Most of the muscle cars during this time were full-size cars. They had large engines, but due to the weight, they were usually slow to accelerate. Pontiac offered a combination of 389 cubic-inch engines in their mid-size Tempest line and called it a GTO. The name GTO comes from Ferrari. It means Gran Turismo Omolgato.
The GTO package included the V8 engine, premium tires, special hydraulic lifters, dual exhaust, manual three and four-speed transmission with a Hurst shifter, heavy-duty clutch, improved suspension, a 3.23:1 rear axle ration, dual hood scoops, GTO emblems, and bucket seats. The 389 cubic-inch engine was rated at 325-348 horsepower depending on the configuration and modification of the engine. The 428 ft-lbs of torque was even more astonishing. Placing this mammoth engine in a mid-size sedan created a vehicle that was untouchable. It was available in both the coupe or convertible body styles. Pontiac sold nearly 32,500 GTO's during the first year.
For 1965, the Tempest GTO received cosmetic and mechanical updates. The engine was modified and was now producing between 335 and 360 horsepower with a torque rating at 431 ft-lbs. The headlights of the vehicle were modified; they were now in a stacked configuration. The dual hood scoop was replaced with a single hood scoop. Over 75,000 examples were sold in the second year.
A dealer cold air induction kit for the Tri-Power cars helped stimulate sales and increased the horsepower of the vehicle. The induction kit made use of the hood scoop and brought about the Ram Air package.
In 1966, the GTO became its own model. There were styling changes mostly concentrating on the roof and the rear lights. The engines were unchanged, however, during the middle of the year, the multi-carburetor setup was no longer offered. The GTO was still more popular than ever, selling 96,946 examples during 1966.
In 1967, a new 400 cubic-inch engine was introduced. The horsepower rating was between 255 and 360 horsepower depending on the configuration. The torque rating was between 397 and 438 ft-lbs. Minor styling changes occurred, mainly the grill and the rear of the vehicle. During the 1967 model year, nearly 82,000 GTO's were sold.
In 1968, the wheelbase was expanded to 112 inches and now sat atop General Motors split wheelbase A-body. Major styling changes occurred. A rubber bumper labeled the Endura, adorned the front of the car. Hidden headlights were optional equipment. The engine choices remained the same but the horsepower and torque were increased. The 440 was not producing between 265 and 360 horsepower while the torque ranged from 397 through 445 ft-lbs.
In 1969, the competition was becoming fierce. To compete, Pontiac offered a package on the GTO that included body paint, rear spoiler, decals, and a 366 horsepower, Ram Air III V8. A Ram IV V8 could also be purchased, increasing the horsepower rating to 370. Still a very successful year for Pontiac, there were more than 72,000 GTO's sold.
In 1970, the GTO once again received styling changes. There were now four exposed headlamps. The rear engine was redesigned and the body received new creases. The base engine was dropped. A 455 cubic-inch engine was introduced. The 400 cubic-inch engine produced between 350 and 370 horsepower. The 455 cubic-inch V8 produced between 360 and 500 horsepower. Sales were still strong but dropping. A little more than 40,000 GTO's were sold.
In 1971, sales continued to drop. Only about 10,000 were sold. GM announced that due to rising emission and safety regulations, compression ratings would have to be reduced and all engines would need to run on unleaded fuel. The horsepower ratings began to decrease. Due to a heavier chassis, introduced a few years prior, and lower horsepower ratings, the vehicle was losing its ability to be competitive. More bad news for the GTO; this was its last year as an independent model. The front end of the vehicle received minor styling updates.
In 1972, the Judge and convertible options were no longer offered. The horsepower ratings continued to go the same direction as the sales figures: down. A little over 5,800 vehicles were sold. The horsepower output was between 250 and 300. The 400 and 455 cubic inch engines were both offered.
In 1973, only 4806 GTO's were sold. The engine horsepower decreased as well, now 230 through 250. Its muscle car status was officially gone.
The 1974 production year was the last for the GTO. It was now an option on the Ventura model line-up. It came as a coupe or a hatchback. A 350 cubic-inch engine was the only one being offered. With a 200 horsepower rating, the car was dying a slow and very painful death. A little over 7000 vehicles were sold with the GTO option.
There were a few reasons for the GTO's decline. The muscle car era was coming to a close - or just being redefined and awaiting a revitalization. Government and safety regulations were becoming more strict. There were tough fuel regulations that severely limited the output of the engines but promoted better fuel economy. Insurance charges increased making these machines out-of-reach for many consumers. The cars became heavier and heavier. The engine sizes decreased; The cost of ownership increased. The muscle car era was destroyed.By Daniel Vaughan | Jun 2018