General Motors sees a growing need for rear-wheel-drive cars in its product portfolio, and such an influx requires either an unimaginably flexible platform or a series of rear-drive component sets. Since “unimaginably flexible” isn’t something GM does well, the company is in the midst of dropping, reworking, and creating rear-drive architectures.
General Motors currently sells rear-drive cars built off of one of three architectures: Y-Car, Sigma, and Zeta. The first underpins only the Corvette—an anomaly in the company’s platform strategy. But the latter two volume platforms grew from a program dating to the early 1990s called Global Rear-Wheel Drive (GRWD in GM-speak). The plan was to use GRWD to build some Cadillacs plus a slew of Holdens for Australia. GRWD was doomed to failure because the Cadillac models required significant cost increases that couldn’t be absorbed by the Holdens, which are sold in vast numbers as razor-margined company cars. The project then splintered and evolved into Sigma and Zeta.
While only three Cadillacs have been spun from Sigma—the previous-gen SRX, the STS, and the current CTS—Zeta serves as the base for products as diverse as the Chevy Camaro, the El Camino–like Holden Ute, and even a Buick Park Avenue for China. All of the Zeta vehicles do have one thing in common, though: They’re porky. When Zeta development was in full swing, Holden management decreed that the Commodore (and all its variants) would ace the Australian NCAP crash tests, but the brand’s price sensitivity meant that extensive use of costly high-strength steel was out. And so the Zeta cars were made strong the old-fashioned way, with mass.
New Stuff: Two RWD Platforms On the Way
Today’s Zeta will morph into the lighter and even more flexible Zeta II for 2015, at which point the Camaro will move onto the Alpha component set also used by Cadillac’s ATS and next-gen CTS. Before that happens, though, Chevy will sell a pair of Zeta-based cars. Actually, the first of these is already on sale—if you’re a state, county, or municipal government that’s allowed to purchase imported products. (Many departments have rules that prevent them from purchasing vehicles not assembled in America.) The vehicle is the Chevrolet Caprice PPV.
The second vehicle, of course, is the most interesting. Perhaps as a way to justify future North American production of its cop car, perhaps simply because Chevy “gets it,” a civilized, civilian take on the PPV joins the model lineup next year. Wearing the SuperSport badge, the car will initially ride on the current Zeta platform and be offered exclusively as a four-door sedan. The SuperSport name and styling also will be applied to the 2013 Chevrolet NASCAR entry. The launch powerplant for the roadgoing car is expected to be the Camaro SS’s 6.2-liter V-8, pumping out something on the high side of 415 hp. A version of GM’s latest 3.6-liter V-6 will be added after the launch for the weaker of heart; we’d expect this engine to produce at least 320 hp. The SuperSport and the Caprice PPV will then migrate to the Zeta II platform in time for the 2015.5 model year. When this happens, full production will shift to North America, thereby delivering a much larger market for the cop version. In addition to the SuperSport sedan, a cropped-rear-overhang sport wagon and a Ute pickup are being considered for the North American market.
Zeta II also will be used for two Chinese-market Buicks starting in late 2014, and one or both of these cars could arrive in North American showrooms if it’s determined that brand needs large rear-drive cars. Conspicuously absent from the Zeta II plans is anything from Cadillac. That’s another story—and another platform.
