2017 GMC Sierra: The 2017 GMC Sierra is a full-size pickup truck that is the corporate twin to Chevrolet Silverado. It competes with the Ford F-150, Ram 1500 and Toyota Tundra. For 2017 it adds a few new features. It's available in regular cab, double cab and crew-cab layouts.The Sierra offers three engines: A 285-horsepower, 4.3-liter V6, a 5.3-liter V8 that makes 355 horsepower and a 420-horsepower, 6.2-liter V8. The V6 mates to a six-speed automatic transmission, while the 5.3-liter V8 is available with either a six-speed automatic transmission or an eight-speed automatic. The 6.2-liter V8 is available with an eight-speed automatic transmission. The Sierra is available with either rear-wheel drive or all-wheel drive. Maximum towing capacity is 12,500 pounds. Bed sizes are 5.8, 6.6 or 8 feet, depending on trim and cab configuration. An available eAssist hybrid system is offered.EPA-estimated fuel economy is 18 mpg city/24 mpg highway (17/22 with four-wheel drive) for the 4.3-liter V6, 16/23 for the 5.3-liter V6 with the six-speed automatic (16/22 with 4WD), 16/22 with the 5.3-liter V8 and the eight-speed automatic transmission (15/20 with four-wheel drive) and 15/21 for the 6.2-liter V8 (15/20 with four-wheel drive).The Sierra is available in base, SLE, SLT and luxury Denali trims. Available features include 18-inch wheels, 20-inch wheels, off-road suspension, infotainment system, Apple CarPlay, Android Auto, navigation and 4G wi-fi hotspot.Available safety features include dual-front, side-impact and head-curtain airbags; traction control, stability control, trailer-sway control, hill-start assist, rollover mitigation, rearview camera, forward-collision alert, lane-keep assist, front and rear park assist and low-speed forward automatic braking.