That would depend on what year it is , the 2010 Ford Mustang GT is rated at 315 horsepower
215 hp
315 hp/325 ft-lbs of torque is the power rating on the 2010 mustang.
412 hp
The 2006 Ford Mustang GT has ( 300 horsepower ) from the factory
300 horsepower
For a 2008 Ford Mustang GT : I believe that is rated at ( 300 horsepower from the factory )
265 stock
300 horsepower
260 horsepower
260 horsepower
157 hp