The 2011 Ford Mustang already packs a plentiful 412 horsepower under it’s well-contoured hood, but for some enthusiasts there is no such thing as enough power. And what makes owning a Mustang so great is that there are countless ways to upgrade your ride. Roush has done it’s fair share of Mustang modifying, and that trend continues for 2011. The new 5XR is Jack and the gang’s latest stab at ‘
