Future Chevy Impala

The car you see here is a rendering based on one of two design proposals under consideration for the 2010 Chevy Impala, a rear-drive sedan to be built on the same Zeta rear-drive architecture as the 2009 Camaro and-as we revealed exclusively last month-also likely to underpin an all-new Pontiac Grand Prix.

Unlike the Grand Prix, which is being pitched as a mildly tweaked version of the all-new Australian-designed and engineered Holden Commodore slated to make its debut at the Chicago Auto Show in February, the new Impala will feature unique sheetmetal from bumper to bumper.

A rear-drive Impala is a logical move for Chevy. It allows GM to increase the Impala's size, making it a clear step up from the all-new Malibu due next year. It also allows Chevy to offer a mainstream car with powertrains of more than 300 horses, including a range of V-8s. Finally, it provides a foundation for a two-tier Chevy range, composed of front-drive small and medium-size cars and rear-drive larger cars.

Building a new Impala off the Zeta architecture also will enable GM to spread some of the investment required for the Camaro across two model lines, as the cars will share mechanicals and numerous sheetmetal components under the skin. That eases the pressure on the Camaro to return the same profit margins Ford needs to justify building the Mustang, which shares few parts with any other FoMoCo vehicle.

Final decision on the new Impala's styling isn't likely until next year. But the car will feature Chevy's bold new corporate grille and an interior that builds on the substantial improvements in quality and presentation shown by the new Tahoe and Suburban.

Zeta Rear Suspension

NEED TO KNOW

6.2-liter V-8 is likely to be the top engine. Expect at least 400 horsepower, with cylinder deactivation for improved fuel economy. Also likely to be available will be GM's high-feature 3.6-liter V-6 and a 5.3-liter V-8.

Standard transmission is likely to be GM's new six-speed automatic. Performance versions, badged SS, probably will be offered with a six-speed manual.

Bold new grille is similar in execution to the 2008 Malibu's. Front overhang is short, and the wide front track means the wheels are pushed right to the corners of the car, giving it a sporty stance.

Fast backlight gives a rakish, almost coupelike profile that pays homage to the beautifully proportioned Impalas of the late 1960s. Rear deck is short and trunk opening narrow to accentuate strong shoulders.

Zeta rear suspension also will be on new Camaro and Pontiac Grand Prix. Features beefy L-shaped single upper link, two lower links, and adjustable toe-control link. Coil-over shocks keep entire assembly compact.

HSV's Hot Holdens
412 horsepower and rear drive. How to do a proper Impala SS or Grand Prix GXP
By Angus MacKenzie

Holden Special Vehicles, the Holden hot shop jointly owned by GM's Australian subsidiary and former F1 team owner Tom Walkinshaw, has launched its versions of the all-new, Zeta-based Holden Commodore. More powerful and more aggressively styled, the new HSV cars show how GM could put together performance versions of a rear-drive Impala or a Pontiac Grand Prix off the same architecture.

Base engine across the HSV range is a 412-horse version of the 6.0-liter LS2 V-8 used in the Holden-based Pontiac GTO. Transmission choice is a Tremec T56 six-speed manual or GM's slick new 6L80E six-speed auto. Holden sources claim test mules have consistently run 0 to 60 in under 5.0 seconds. Standing quarter-mile times should be in the 12-second bracket.

Brakes are monster 14.3-inch discs up front and 13.7-inch units at the rear, with AP Racing calipers. The top of the range GTS shown here also gets 20-inch alloy wheels and adjustable Magnetic Ride Control shocks by Delphi, as used in the C6 Corvette and the Cadillac STS-v.

Zeta Architecture

Apart from the usual wheels and wings, the visual changes over the standard Holden Commodores include unique front fenders with a prominent side vent and new taillamps. Inside are sports seats and extra gauges-voltage, oil temperature, and oil pressure.

Now, here's the best bit: HSV sources haven't ruled out building a limited-run model powered by the 7.0-liter, 502-horse LS7 from the Corvette Z06. Yeah, it fits, and a car could appear at the Sydney motor show in October of next year. A 502-horsepower four-door sedan? Now that's what we call a musclecar.