Shelby

2012 Mustang Shelby GT500

The Mustang Shelby GT500 retains the 5.4-liter V8 developed for the Ford GT supercar, rather than adopting a variation of the new 5.0-liter V8 introduced in the standard 2012 Mustang GT. Horsepower increases by 10 from the 2010 GT500, to 550 hp at 6,200 rpm (peak torque holds at 510 lb-ft), but that's a relatively minor part of the story. The 2012 GT500 gets a new aluminum engine block, cast by Honsel in Germany and finished with a metallurgical process called Plasma Transfer Wire Arc. Steel cylinder liners are sprayed in under extreme pressure at 35,000 degrees Fahrenheit, then machined to a thickness of 150 microns.

As result, the 2012 block weighs 102 pounds less than the previous cast-iron block. Other weight (and fuel) savers include an electric power-steering pump. Charge cooling capacity for the Roots-type supercharger increases 40 percent, thanks to a larger, two-layer intercooler. Bottom line, the GT500's curb weight drops 120 pounds compared with the 2010, to 3,820 pounds. Nearly all of the reduction comes over the front axle in what is a nose-heavy car.

The 2012 GT500 also has aerodynamic improvements and sound-dampening refinements that reduce interior noise levels 20 percent, according to Ford. For the first time, it offers an optional Performance Package developed from the limited-run 2009 GT500 KR. The package includes a limited-slip differential with a shorter 3.73 gear, stiffer springs that lower ride height slightly, forged wheels, Goodyear's latest-gen Eagle F1s (255/40Z-19 front, 285/35ZR-20 rear), and unique, thinner hood stripes.