The Mustang GT has had a 5.0 liter engine in its bay for almost 30 years.  It was only in 1996 that Ford went with the 4.6L engine.  Well now the 2011 Mustang GT will get an increase in displacement to meet the 5.0 liters of days gone by.  Since the Mustang was redesigned in 2010, not much has changed on the outside; but a lot has changed under the hood.
In order to deal with the Chevy Camaro and its 426 horsepower, Ford need to add some more muscle for the 2011 model year.  So a bump in displacement and a reworked engine will net 416 horsepower; enough to contend with the Camaro SS 426HP and the Challenger SRT8 425HP.  The Mustang already is the best handling car of the bunch, and with the added horsepower, the GT should establish itself once again at the top of the muscle car heap.

Chevrolet struck a heart string with buyers when the 2010 Camaro came stock with a V-6 engine that produced 300 hp while getting 30 MPG on the highway.  Ford has decided to follow suit and will introduce a 3.7 liter, V-6 engine in the stock Mustang that will generate 305 Hp, which is more than the Camaro V-6.  Fuel Economy numbers for this engine is right at the 30 MPG mark on the highway.