Chrysler’s Hellcat V-8 Rated at 707 hp

Chrysler Group LLC says the output of its new supercharged 6.2-liter Hemi V-8 Hellcat engine has been certified at 707 hp and 650 lb-ft of torque.

The monster engine will debut by September in the 2015 Dodge Challenger SRT sport coupe. Chrysler describes the model as the world's most powerful muscle car ever.

When Chrysler announced the engine in May, it predicted output of "more than 600 hp." The engine's actual performance compares with 640 hp and 640 lb-ft of torque for Chrysler's naturally aspirated V-10-powered SRT Viper sports car.