Pontiac GTO

📸: Photo courtesy HotRod.com

No, they aren't supercars, and the earlier models were definitely not sports cars, but we're going to give General Motors credit for attaching the GTO name to a car that actually lived up to it. Not the homologation part, obviously, but Pontiac was GM's performance division, and the original GTO did indeed embody the concept of grand touring sportiness and style.

The fact of the matter, though, is that the Pontiac GTO was a muscle car, if not the FIRST muscle car. Born in 1964 (just a year or two after the original Ferrari GTO), the Pontiac GTO started as a option package on the already-existing mid-sized Tempest coupe. The GTO option included a 6 liter V8 making 325 horsepower... more than Ferrari's 3 liter V12 GTO. A triple carburetor option could raise the horsepower to 348. A 1965 version is shown above.

📸: Photo courtesy HotRod.com

In 1966, it became its own model, and power was increased to 360 horsepower. The design was curvier, and Pontiac sold nearly 100,000 of them. Quite a difference from Ferrari's limited production. Above, a 1966 convertible.

📸: Photo courtesy Hemmings.com

In 1968, General Motors debuted the fastback body style for it's A-model lineup. The '69 and '70 models probably were the highwater mark for the car, as encroaching emissions regulations and fuel economy concerns would strangle the big American V8s for the next 10 years.

📸: Photo courtesy RoadandTrack.com

Pontiac messed around with the GTO name for decades before they finally gave it what it deserved: a 400 horsepower Corvette engine. That came in 2005, when GM dropped the 6 liter V8 in the rebadged Holden Monaro. This made it by far the most powerful Pontiac GTO of all time, and most likely the fastest, too. Reported top speed with the limiter in place was 160 mph. It would reportedly top 188 mph with the limiter defeated. A true GTO (er, again, without the homologation part)!