Ford revised all the Mustang's engines for 2011. The new V6 is a smaller 3.7 L (227 cu. in.) aluminum block engine weighing 40 lb (18 kg) lighter than the outgoing version. The engine produces 305 hp (227 kW) and 280 lb·ft (380 N·m) of torque. Ford announced on December 28, 2009 that the 2011 Mustang GT would feature a 5.0 engine (302.15 cid (4.951  L)) that produces 412 horsepower (307 kW) and 390 lb·ft (530 N·m) of torque on "premium fuel" (gasoline with a pump octane rating of 91); on "regular fuel" (gasoline with a pump octane rating of 87), these numbers fall to 402 hp (300 kW) and 377 lb·ft (511 N·m).^[48] The Ford 5.0-liter V8 “Coyote” engine has 32 valves (4-valves per cylinder) with Twin Independent Variable Cam Timing (TiVCT). These cams control intake and exhaust functions of the vehicle to maximize combustion. The transmission includes either a 6-speed automatic or manual. An Electronic Power Assist Steering (EPAS) removes the conventional hydraulic power steering pump. The system does not use belts previously required for steering. An optional Brembo brake upgrade is available. These brakes were previously used on the Shelby GT-500. A pair of 19-inch wheels and performance tires is included.^[49] The Shelby GT500's supercharged 5.4 L block is now made out of aluminum making it 102 lb (46 kg) lighter than the iron units in previous years, and is now rated at 550 hp (410 kW) and 510 lb·ft (690 N·m) of torque.^[50]