America's brashest pony car got a massive do-over in 2010, with the interior, much of the engine, and every panel except the roof brand new, though with the trusted S-197 platform underneath it all. The 2010 Mustang GT500 pushed the envelope even further, mustering the strongest power ever to appear in the 'Stang lineup until that time. Featuring a sequential tri-bar taillight recalling the Shelby GT350 of old, this GT500 model keeps a 5.4 liter DOHC V8 under its hood developing a big, road-ruling 540 horses and 510 ft-lbs of torque. The 3.55:1 gear ratio of the rear axle hurls the 2010 GT500 Pony from 0 to 60 in just 4.5 seconds, giving the occupants a thrilling taste of g-forces. Rolling on 19-inch wheels, the GT500 keeps its engine cool with a hood scoop and manages downforce with a spoiler. For 2011, the Ford Mustang engineers had great things in store for the GT500, refitting it with a 5.4L aluminum V8 102 lbs lighter than the previous year's engine. Now getting 15/23 mpg city/highway, the GT500 raced out of the “Gas Guzzler Tax” category while gaining another 10 horsepower. Lighter, powered up, with a better stance, 2011 and 2012 Mustang GT500s (which are nearly identical) can do the quarter-mile in just 12 seconds, while going from zero to 60 in 4 seconds, half a second faster than the 2010 model. The 2-door coupe trim cost $46,725 MSRP in 2010, rising to $48,645 in 2011 and $48,810 in 2012; the convertible trim fetched an MSRP of $51,725 in 2010, $53,645 in 2011, and $53,810 in 2012.