The 2011 Ford Mustang's new 3.7-liter V6 now has all-aluminum construction, dual overhead camshafts and variable valve timing. The extra gears help the Mustang V6 earn a laudable 31 mpg highway EPA fuel economy estimate. Both transmissions for the V8-powered Mustang GT (manual and automatic) are similarly upgraded to six-speed units.The 2011 Ford Mustang is available as a coupe or convertible.