Alpha Platform: GM To Make Midsize RWD Cars

General Motors’ globalization of platforms has paid dividends for the autoconglomerate. The unitized development has no doubt saved millions of dollars in development costs and has provided some cutting edge vehicles. Take for instance the Delta platform, introduced in the early part of this decade, which is used for everything from the Chevrolet Cobalt to the Opel (and now Saturn) Astra. Likewise, GM has had plenty of success with the Epsilon platform that has seen action in Germany, Sweden and North America.

A recent report by Edmunds states that GM will be branching out in two different directions for its future midsize sedans. The first one has been clearly established, the Epsilon II architecture which will be featured on the soon to arrive 2008/9 Opel Vectra, and shortly thereafter the next-generation Saturn Aura. Other vehicles that will be underpinned using this global platform include the next-generation Saab 9-5, followed a few years later by the next Saab 9-3. It will be quite some time before the Chevrolet Malibu switches over to Epsilon II, considering that theall-new 2008 Malibu has yet to arrive, and it uses current Epsilon I technology.

But according to this report, General Motors wants to create more than just simple, run of the mill front-wheel drive midsize cars. It appears that GM has set its Australian division, Holden, to develop a midsize rear-wheel drive platform for global use, called “Alpha”, that will fit in under the Zeta vehicles and the Sigma architecture, which is exclusively used by Cadillac.

The forthcoming Alpha platform is speculated to be modular like the Epsilon, and capable of producing vehicles between 4,300 - 4,600 mm (170 and 180 inches) in length, a size more compact than any of the current Epsilon cars, though the projected 2,800 mm (110-inch) wheelbase would ensure plenty of interior room for passengers. Because size is an issue that GM must take into consideration, the platform would feature completely new suspension designs (rather than a typical strut setup a four-link system has beensuggested), which would ensure that Alpha is more than just a shrunken Zeta. The Alpha cars would be powered by four-cylinder and six-cylinder engines, but not eight cylinder engines as they would not fit in the prescribed space.

The report predicts the first vehicle to utilize the platform would be the successor to the Saab-based Cadillac BLS, which would give the American luxury brand a direct competitor to the BMW 3-Series and Mercedes-Benz C-Class in terms of size and drivetrain layout. Pontiac’s G6 would eventually move to the Alpha platform too, projected to take place in around five years, but not before the new generation arrives on the Epsilon II. After developing the architecture, it’s only logical that Holden would receive a version of its own.

Given GM’s recent fixation on developing new rear-wheel drive vehicles, such as the Camaro, the next-generation Impala, Pontiac G8, Caddy CTS and others, plus the baby Kappa sports cars, including the Saturn Sky, Pontiac Solstice and Opel GT, it’s no surprise that GM wants to bring RWD back to more mainstream vehicles.