The fifth generation Mustang committed even more to the retro styling of earlier models with a truly muscular look. The front grille and headlight placement highly resembled the earliest Mustang models. For the first half of this generation, the Mustang featured a 4.0-liter V6, a 4.6-liter V8 or a 5.4-liter supercharged V8. Transmissions included a five or six-speed manual or a five-speed automatic. The second half of this generation saw a reworked design for better aerodynamics, though it looked ostensibly the same save for some other cosmetic details such as a redesigned emblem and headlight placement. A 5.8 liter V8 became the biggest engine offered, and a six-speed automatic transmission was introduced as well. The GT-500 came with a 500-horsepower engine, and the limited-edition GT500KR offered a 5.4-liter engine with 540 horsepower. The 2010 model year came with an optional Track Pack performance package. A new Shelby GT350 made its way on the streets in the 2016 model year.