Fifth generation (2005–present)

Main article: Fifth-generation Ford Mustang

2005-2008 GT Coupe

At the 2004 North American International Auto Show, Ford introduced a completely redesigned Mustang, codenamed "S-197," that was based on an all-new D2C platform for the 2005 model year. Developed under the direction of Chief Engineer Hau Thai-Tang and exterior styling designer Sid Ramnarace, the fifth-generation Mustang's styling echoes the fastback Mustangs of the late 1960s. Ford's senior vice president of design, J Mays, called it "retro-futurism."

The fifth-generation Mustang is manufactured at the AutoAlliance International plant in Flat Rock, Michigan. The base model is powered by a 240 hp (179 kW) cast-iron block 4.0 L SOHC V6, which replaces the 3.8 L pushrod V6 used previously. The Mustang GT features an aluminum block 4.6 L SOHC 3-valve Modular V8 with variable camshaft timing (VCT) that produces 300 hp (224 kW). The 2005 Mustang GT has an approximate weight to power ratio of 11.5 lb/bhp. The base Mustang comes with a standard Tremec T-5 5-speed manual transmission while Ford's own 5R55S 5-speed automatic, a Mustang first, is optional. Though the Mustang GT features the same automatic transmission as the V6 model, the Tremec T-5 manual is substituted with the heavier duty Tremec TR-3650 5-speed manual transmission to better handle the GT's extra power.[25]

A revised 2010 model year Mustang, due to be launched in early 2009, was unveiled on the internet ahead of the 2008 Los Angeles International Auto Show.[26] Though sharing the same overall dimensions as the 2005-2009 mustang, the sheet metal is for the most part all new. The 2010 mustang is reported to have the same drivetrain as it forebear, although benefiting from technology showcased on last years bullit. This includes bumping power to 315hp and 325 lb ft of torque, and achieving a better overall mid range torque curve when ran on premium fuel. Some automotive magazines are reporting that the new mustang may get a better engine lineup in 2011 similiar to what how ford handled the Escape redesign with more efficient engines appearing a year after the refresh.