The Mustang has been a popular car among teenagers and young adults pretty much since its conception. In the early years it wasn't the horsepower and torque monster that later Shelby and Boss Mustangs became, but its popularity was almost instantaneous. Then the Mustang when through a strange period in the '70s where they lost their edge, some might even say their appeal. All that changed with the introduction of the 5.0 Mustang in the '80s and again just recently with the newest 5-liter Mustang V8 for 2011.

Another Mustang that returned to the scene with the retro redesign the Mustang has seen over the last couple of years is the Shelby GT500. Back in the day the GT 390 and the Shelby GT500KR were some of the fastest Mustangs you could get, with the later having a 428 Cobra Jet V-8. However, the boys at Top Gear have yet again brought us back down to reality. Have you ever wondered whether the newest GT500 really makes that 500 horsepower that is advertised? What about those classics, how does one of those hold up over the years? Check out the video below and see the answers in living color (keep in mind that horsepower at the crankshaft and at the wheels will always differ).