The 2009 Mustang did *not* have a 5.0L engine. The 5.0L "Coyote" engine was introduced in the 2011 Mustang. The 2009 Mustang offered a 4.0L V6 and a 4.6L V8. The horsepower varied slightly depending on the trim level, but generally:
* 4.0L V6: Around 210 horsepower
* 4.6L V8: Around 300-315 horsepower (depending on the specific model - GT, etc.)