Fitted with a supercharged single overhead camshaft 7-litre straight-6 engine[1][7] producing 200–300 metric horsepower (150–220 kW) and over 500 lb⋅ft (680 N⋅m) of torque (depending on the state of tune),[7] the SSK had a top speed of up to 120 miles per hour (190 km/h), making it the fastest car of its day.[8] The supercharger on the SSK's engine was operated by a clutch that was engaged by fully depressing the throttle pedal and then giving the pedal an extra push. Backing off the throttle pedal disengaged the supercharger clutch.[6]