The Chevrolet Impala returns for 2009 available in several trims: LS, LT, LTZ, and SS. The base engine on the LS and LT is a 3.5L V6 engine, while the 233 horsepower 3.9L V6 is optional on the LT and standard on the LTZ. A 5.3L V8 powers the SS model and generates 303 horsepower and 323 lb-ft of torque. All engines are mated to a four-speed electronically controlled automatic transmission. Standard equipment across the board includes side-impact airbags, a remote keyless entry system, OnStar communication system, daytime running lights, and a theft-deterrent system. Optional features include engine block heater, split bench front seat, power glass moonroof, 6-disc CD changer, and a Bose speaker system.