No manual gearbox for fastest-ever Mustang Shelby GT500

Ford this year will unbridle the most powerful "Pony" in its stable: a street-legal 700-plus hp Mustang Shelby GT500. But this third-generation thoroughbred will be a horse of a different color; it's the first GT500 to not offer a manual transmission.

Ford Performance paired the car's hand-built, supercharged 5.2-liter V-8 engine with a seven-speed automatic gearbox. That's the only powertrain option available. That's partly a performance play, the dual-clutch transmission is capable of shifts in under 100 milliseconds, faster than a manual and partly a sign of where the company is under cost-conscious CEO Jim Hackett. Although popular among enthusiasts, the GT500's sales volume would not justify the added expense of a second powertrain.

With its supercar-level powertrain, the all-new Shelby GT500 is the quickest street-legal Mustang ever built, with 0 to 100 km/ times in the mid-3-second range.

It comes with a revised suspension, a new electronic power steering unit and front and rear coil springs. The vehicle will be offered with a base "handling" package and optional track package.

The base model has a rear seat, but the track package doesn't to save weight. Both come with a rotary shifter for the automatic transmission, a 12-inch standard digital instrument cluster and a rear spoiler, although the track version offers a larger spoiler.

The GT500 will be available in 11 colors, including three new ones: Red Hot, Twister Orange and Iconic Silver.

Ford last offered the snake-badged GT500 for the 2014 model year. This is the first time in 50 years, officials said, that a GT350 and GT500 will both be made in the same model year.

New family of Mustangs will hits dealerships this fall.