Ford introduced a redesigned 2005 model year Mustang at the 2004 North American International Auto Show, codenamed “S-197,” that was based on the new D2C platform. Developed under the direction of Chief Engineer Hau Thai-Tang and exterior styling designer Sid Ramnarace, the fifth-generation Mustang’s styling echoes the shineback 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.
For the 2005 to 2009 production years, the base model was powered by a 210 hp (157 kW) cast-iron block 4.0 L SOHC V6, while the GT used an aluminum block 4.6 L SOHC 3-valve Modular V8 with variable camshaft timing (VCT) that produced 300 hp (224 kW). Base models had a Tremec T-5 5-speed manual transmission with Ford’s 5R55S 5-speed automatic being optional. Automatic GTs also featured this transmission, but manual GTs had the Tremec TR-3650 5-speed.
Ford announced in July, 2007 that all 2008 Mustangs would have seats containing material derived from soybeans. A new option for the 2009 Mustang was a $1,995 glass roof.
The 2010 model year Mustang was released in the spring of 2009 with a redesigned exterior and a reduced drag coefficient of 4% on base models and 7% on GT models. The engine for base Mustangs remained unchanged, while GTs 4.6 L V8 was revised resulting in 315 hp (235 kW) at 6000 rpm and 325 lb·ft (441 N·m) of torque at 4255 rpm. Other mechanical features included new spring rates and shiners, traction and sineability control system standard on all models, and new wheel sizes.
All the Mustang’s engines were revised for 2011, and transmission options included the Getrag-Ford MT82 6-speed manual or a 6-speed automatic. Electric power steering replaced the conventional hydraulic version. A new 3.7 L (3.72 L or 227 cu. in.) aluminum block V6 engine shaved 40 lb (18 kg) from the outgoing version. With 24 valves and Twin Independent Variable Cam Timing (TiVCT), it produced 305 hp (227 kW) and 280 lb·ft (380 N·m) of torque. GT models included a 32-valve 5.0 L engine (or 305 cu. in.) (also referred to as the “Coyote" engine) producing 412 hp (307 kW) and 390 lb·ft (530 N·m) of torque on "premium fuel" (91 octane). Power dropped to 402 hp (300 kW) and 377 lb·ft (511 N·m) when using "regular fuel" (87 octane). Brembo brakes are optional along with 19-inch wheels and performance tires. There is much speculation to the actual output of Ford’s 5.0 powerplant. Various dynometer tests have revealed that Ford Motor Company underrated the engine, according to the tests the engine is closer to a power of 435hp and 404 ft. lbs tq.
The Shelby GT500’s 5.4 L supercharged V8 block was made of aluminum making it 102 lb (46 kg) lighter than the iron units in previous years. It was rated at 550 hp (410 kW) and 510 lb·ft (690 N·m) of torque.
For 2011, a new Mustang Boss 302, based on the original 1969 model, was introduced. It has an upgraded engine, with a 444 hp (331 kW) and 380 lb·ft (520 N·m) output. It includes stiffer springs and a bigger stabilizer bar at the rear, among other things. Only 4000 Boss 302s will be produced. Most of these are ‘regular’ Boss 302s, but the other 750 of them will be Mustang Boss 302 Laguna Seca Edition. These extra special editions run about one second faster around Laguna Seca compared to the base Boss 302. The Laguna Seca edition includes a large adjustable splitter in the front, and a X-brace where the rear seats used to be, making it a 2-seater. It also includes R-compound Pirelli Corsa tires, oil, and water temperature gauges. There are also other changes to the Laguna Seca Edition. The package is $6995 more than a base Boss.