CHICAGO -- Ford showed off the most powerful car in the Mustang lineup this week at the 2010 Chicago Auto Show.

The 2011 Ford Shelby GT500 is all about the engine. The car starts with a Mustang (which was all new for 2010) and cranks up the fun with a 550-horsepower engine that also churns out 510 pound-feet of torque.

The 5.4-liter engine was developed by Ford's Special Vehicle Team (SVT) and boasts a 10-horsepower increase over the previous engine. The new engine is also all-aluminum, shaving 102 pounds off the previous cast-iron model.

Thanks to the lighter engine and improved airflow under the car, the new GT500 gets slightly better gas mileage than its predecessor. It's expected to get 23 mpg on the highway and 15 mpg in the city.

The GT500 will also be available as a convertible, or with the glass top that can be found on the standard Mustangs.