For 2008, Chevrolet offers an electronic stability system for the first time on the Impala. General Motors' StabiliTrak system is standard on higher-level LT, LTZ and SS models. Impalas compete against the Ford Taurus, Chrysler 300 and Toyota Avalon. The Impala nameplate dates back to 1958, when it was the top-end member of Chevrolet's full-size car lineup.
Engines include a 3.5-liter V-6, a larger 3.9-liter V-6 and a 5.3-liter V-8. For 2008, both V-6s can be ordered with ethanol-based E85 compatibility, and those with the larger V-6 have a cylinder deactivation system for improved fuel economy. A new luxury package is available for 2008 that combines popular options into one package.
Four trim levels are available: LS, LT, LTZ and SS. The LT trim level has 1LT and 2LT packages that offer different levels of standard equipment. Inside, innovative flip-and-fold rear seat cushions reveal a covered storage area and include grocery bag hooks. The rear seatback folds down to create a pass-thru into the trunk. Interiors also display improved seat-upholstery stitching, low-gloss instrument-panel components and jewel-like dashboard details.
Impalas ride on 16-, 17- or 18-inch wheels. Side curtain airbags are standard. Most models benefit from enhanced antilock brakes and traction control.
Large headlights contain three independent lighting units, and Impalas have grab-style door handles.
SS sedans exhibit a distinct front-end look, led by a dual-split grille that contains a black-diamond crosshatch pattern. Corvette-inspired bright exhaust outlets are installed on SS models. A rear spoiler is standard on the LTZ and SS and optional on the LT.
The base Impala has a softer suspension that's fully independent and rides on 16-inch wheels. Midlevel Impalas receive 17-inch wheels, while the Impala SS gets a sportier suspension with 18-inch wheels. Built on a 110.5-inch wheelbase, the Impala is 200.4 inches long overall and 72.9 inches wide.
Depending on the choice of front seats, the Impala holds either five or six occupants. Nuance sandstone leather seating with French seams on the center cushions is available. The seats have firmer cushions and increased lumbar support.
The instrument panel wraps into the door panels; its double-hump design is reminiscent of early Corvettes. All Impalas except the SS offer a choice of trim: either a wood-trimmed look or a sportier brushed sterling appearance. The Impala SS has a patterned trim panel. Trunk space totals 18.6 cubic feet.
General Motors' OnStar communication system is standard, and an available Directions and Connections service gives audio turn-by-turn directions from an OnStar operator. Manual dual-zone climate control and a remote starter that can warm or cool the car prior to entry are available. Cruise control buttons are mounted on the steering wheel, and auxiliary radio controls are optional, as are heated seats, leather upholstery and power front seats.
A new luxury package on 1LT trims combines popular options into one package, including leather-trimmed interior, antilock brakes, traction control, a rear spoiler and GM's OnStar communication system with Turn-By-Turn navigation.
Impalas can be equipped with one of three audio systems. A standard six-speaker CD stereo includes an auxiliary jack for iPods or other MP3 players. A midlevel system can play MP3-formatted CDs, while a top-end Bose system includes eight speakers and a six-CD changer.
The Impala's 3.5-liter V-6 produces 211 horsepower and 214 pounds-feet of torque. It can now be configured to run on regular gasoline or ethanol-based E85. Uplevel Impalas get a 3.9-liter V-6, rated at 233 hp and 240 pounds-feet of torque. New for 2008, that engine can also now run on E85. That engine receives GM's Active Fuel Management system — formerly called Displacement on Demand — which shuts down half the cylinders under light-load situations, such as highway cruising. Chevrolet says that with the V-6, Active Fuel Management increases gas mileage by as much as 8 percent.
In SS models, a 5.3-liter V-8 generates 303 hp and 323 pounds-feet of torque and includes Active Fuel Management. All three engines work with a four-speed automatic transmission.
Side curtain airbags and seat belt pretensioners for the front seats are standard. All-disc antilock brakes are standard on the LT, LTZ and SS. Traction control is available. Latch child-safety seat attachments go on all second-row seating positions. A tire pressure monitoring system is standard on all models.