The 2018 Impala is powered by one of two engines, each mated to a 6-speed automatic transmission. Engine choices include a 2.5L 4-cylinder making 196 horsepower and a 3.6L V6 making 305 horsepower. The 2.5L features stop/start technology, which shuts down the engine in certain driving conditions to reduce fuel consumption. Chevrolet claims that the V6 is the most powerful naturally aspirated V6 in its class. The Impala comes in trims that include LS, LT and Premier. LS trims are the most basic and feature keyless entry, cloth seats, a 6-speaker 100-watt sound system, the MyLink infotainment system with an 8-inch color display, an 8-way power adjustable driver's seat, steering wheel-mounted audio and cruise controls, rearview camera, automatic headlights, a noise cancellation system, 18-inch wheels, and a 6-month subscription to GM's OnStar service. LT versions get dual-zone climate control, heated mirrors, a leather-wrapped steering wheel and shift knob, nicer 18-inch alloy wheels and a better stereo. The Premier Impala upgrades a number of luxury features. It receives the 3.6L V6 engine as well as a remote starter, keyless access and start, a heated driver and front passenger seats, ambient interior lighting, navigation, 19-inch wheels, HID headlamps, chrome door handles and LED running lamps. Premier Impalas also come standard with a host of extra safety features, including a lane departure warning system, cross traffic alert, blind zone alert and rear park assist. All Impalas feature anti-lock brakes, traction control, OnStar with automatic crash response, stability control and a total of ten airbags.