An iconic name from GM’s former Excitement Division, the Pontiac Grand Prix had a 46-year production run that only ended when the brand itself finally ran out of gas during the financial crisis that began in 2008. Now, the Grand Prix went through its share of changes over time, starting life as a premium coupe to rival the Ford Thunderbird and ending as a family-focused sedan, and making some interesting stops along the way. But one thing that remained constant was the Grand Prix’s ability to offer some of GM’s strongest engines.
Of course, none was rated as strong as the 421-cubic-inch V8 that featured dual four-barrel carburetors and was available as an option in the 1962 Pontiac Grand Prix. That mighty motor cranked out some 405 horses, and with 425 pound-feet of torque on hand, it provided the powerful Pontiac with serious motivation.
That’s the usual story, anyway. In reality, we have to give the 1962 Grand Prix’s horsepower record a bit of an asterisk — which I’ll resolve further on down.
Grand Prix introduced a new formula for fun
The Pontiac Grand Prix debuted in 1962 with a name that was an obvious nod to vehicles with a bit more focus on performance: Formula 1 race cars. Now, no one’s likely to confuse a ’62 Pontiac Grand Prix with the BRM P-578 F1 car that won multiple Grand Prix races — and the F1 driver’s/constructor’s championships — that same year. Yet Pontiac’s coupe certainly brought its share of excitement to American streets.
That was especially the case if you ordered the Super Duty option pack. While it appears only 16 people actually did that, they were rewarded with go-fast goodies including that upgraded 421-cubic-inch V8 and a revised rear axle ratio. With that mill making 405 horsepower, lucky owners could conquer the quarter-mile with times of 14.3 seconds and trap speeds north of 103 mph, flying from 0 to 60 mph in 6 seconds along the way. Not bad for a two-ton car relying on 65-year-old technology.
The Grand Prix also stands out as an early example of an automaker stuffing a big high-performance motor into one of its traditional mass-market cars. It’s recipe that would soon lead to what’s considered the world’s first muscle car, the 1964 Pontiac GTO.
Do new rules make for a new answer?
Remember that asterisk business from the beginning? The reason behind it is that cars such as the 1962 Grand Prix used to be rated based on gross horsepower, which is measured with the engine completely on its own, uninstalled in a vehicle. Automakers switched to using net horsepower in the early 1970s, and that meant measuring while taking into account the power-sapping effects of features like the fuel-delivery system, exhaust system, and vehicle accessories. All that seriously reduces the amount of horsepower actually available to drive the car. Some experts claim reductions on the order of 30% compared to gross horsepower.
Taking that into account, the Grand Prix’s 405 gross horses from 1962 translates to a bit under 285 net hp today. That, in turn, would give the horsepower crown to the 2005-2008 Pontiac Grand Prix GXP, a front-wheel-drive sedan backed by a 5.3-liter V8 that’s good for 303 ponies. Coincidentally, the GXP helped close the circle of life for the Grand Prix with nearly the exact performance scores as its 1962 ancestor. Four decades after the Super Duty rang up a quarter-mile time of 14.3 seconds and a 0-60 mark of 6 seconds,” Car and Driver clocked the GXP at 14.3 and 5.7.
