The Pontiac Muscle Car That Exploited a Loophole Is Vanishing Fast
Let us gather here today to remember the late 1960s and early 1970s powerhouses that we’ve lost. As emission standards increased, muscle cars suffered. Engines were being detuned or discontinued left and right. But a few Pontiac engineers weren’t ready to let go of their high-performance dreams as racing programs were gutted. They exploited a crucial loophole to keep a true muscle car alive for a few extra years.
Pontiac Refused To Fold Under Mounting Pressure
Unfortunately, the 1970 Clean Air Act and new Environmental Protection Agency (EPA) regulations hit muscle cars hard. From 1971 to 1972, the American auto industry switched from measuring gross horsepower to net horsepower. It was measured with all factory accessories like air filters and emissions equipment attached, making power drops appear more severe on paper.
Things only worsened when the 1973 oil crisis struck, leading to tremendous fuel shortages and rapidly increasing fuel prices. Simultaneously, insurance companies drastically increased rates for high-performance cars due to a rise in accidents involving young drivers. Muscle cars were suddenly too expensive to buy and insure on top of higher fuel costs.
The Chevrolet Chevelle SS was reduced from 450 gross hp to about 235 to 275 net horsepower by 1973, and the SS package was phased out. Then the Corvette’s output plummeted from 435 net hp to 270. Also, the Ford Mustang downsized to the four-cylinder/V6 Mustang II model in 1974, and the 426 HEMI was discontinued by the end of 1971.
Pontiac faced a little extra pressure under General Motors as it introduced new hardware for all vehicles in 1973, including Exhaust Gas Recirculation (EGR) valves and Transmission Controlled Spark (TCS) spark systems. GM also modified engines to achieve significant pollutant reductions. This forced Pontiac engineers to get creative as they refused to let one powerful build go. It was discontinued in 1974 when it could no longer outrun new regulations.
The 1973–74 Pontiac Firebird Trans Am Super Duty 455 Was The Last True Muscle Car
After rivals folded, the 1973–74 Pontiac Firebird Trans Am Super Duty 455 managed to survive a few extra years by taking advantage of an engine loophole. Under the Clean Air Act, auto manufacturers were required to prove that new engines could comply with federal pollution limits over five years or 50,000 miles.
But Pontiac based the Super Duty 455 on its existing architecture instead of submitting it as a new design to bypass the certification process. The engine only faced a 4,000-mile break-in certification instead. Engineers also stockpiled thousands of heavy-duty, racing components instead of scrapping them, which would have led to financial losses.
In 1973, the 455 cubic-inch (7.5-liter) OHV SD-455 V8 engine delivered a factory-rated 310 hp and 395 lb-ft of torque. The Firebird Trans Am SD 455 flew from 0 to 60 mph in about 5.4 seconds and completed a quarter mile in roughly 13.5 seconds with a top speed of around 125 mph.
In 1974, the EPA caught on to what Pontiac was doing and forced a re-certification. Pontiac was forced to replace the rugged Ram Air IV-style camshaft for a milder setup. As a result, power was reduced by 20 ponies to 290 hp, but at least this made insurance surcharges a bit more affordable.
The 2008–09 Pontiac G8 GXP Serves As Another Last Stand
During the late 2000s, General Motors was struggling financially and losing billions before the 2008 economic recession struck. Pontiac knew it was in danger as it was forced to sell rebadged Chevrolet models. It was clearly the red-headed stepchild of the family but decided to go out with a bang.
The 2008–09 Pontiac G8 GXP was the most powerful and the final high-performance muscle sedan built before the brand was discontinued in 2010. Pontiac built this car despite knowing that General Motors was facing steep financial losses. It was engineered and built in Australia, then quietly imported to North America to defy GM standards as a now-or-never project.
This swan song packs a potent punch with the 6.2-liter LS3 V8 engine that was borrowed from the Corvette. It cranks out 415 hp and 415 lb-ft of torque. The G8 GXP accelerates from 0 to 60 mph in about 4.5 seconds and runs the quarter mile in 13.0 seconds at 109.6 mph. It features a factory-governed top speed of around 146 mph.
The G8 GXP may have been more popular had it been promoted or marketed by GM, but the automaker feared that it would hurt Cadillac and Chevrolet sales. Only an estimated 1,829 models were built before Pontiac got the axe, so General Motors could streamline production. However, it paved the way for the 2014 Chevrolet SS sedan.
Only One Of These Rebellious Pontiac Models Is Affordable To Own
If you would like to own a surviving 1973–74 Pontiac Firebird Trans Am Super Duty 455, good luck. Only about 1,296 models were built, and it’s unclear how many still survive today. They only go to auction a few times a year.
Models in fair driving condition sell for between $41,000 and $55,000. Next, examples in good condition sell for between $88,000 and $95,000. Survivors in pristine condition fetch between $111,000 and over $154,000.
The 2008–09 Pontiac G8 GXP is still rare, but it’s easier to get. It still only goes to auction a few times a year. Models in good condition often sell for between $21,733 and $29,200. GXPs in excellent condition often fetch between $34,200 and $43,267 at auction. Then low-mileage models in pristine condition sell for between $47,333 and over $55,467.
Source: Hemmings, Hagerty
Related posts
Latest Post
No Comments