One reason is that a platform can't be seen, except during the development and manufacturing process. Unlike a traditional frame, to which running gear and a body are attached, a platform is not an individual component but a grouping of components, the primary one being the floor and inner body structure. To this are attached sub-frames that support the engine, suspension, and other mechanical parts.
Exterior body panels are affixed to the outside of the structure; dashboards, seats, steering wheel and controls go within. A complete platform with running gear can actually be driven prior to the outer "skin" being in place; at manufacturer's proving grounds it is not unusual to see one running around the test track with no skin or, at best, temporary body pieces. These vehicles are referred to by development engineers as "mules."
Platforms have, in recent years, become important to the industry because they can be used with a variety of automobiles in the same family. A platform can be stretched, made wider and taller, can accommodate a range of engines and transmissions. This saves a fortune in development costs, as well as speeding the time it takes to bring new vehicles to market.
So now we see cars made in Europe and America yet sharing the same platforms, though the vehicles appear on the outside to be unique. To the consumer, a Saab, a Saturn or an Opel may be completely different but under those bodies you'll find a platform commonality and even, nowadays, similar engine groups. Fortunately platforms and powertrains can be tuned to provide characteristics best suited to a product and its brand identity.
Volkswagen has led platform design more than any other company, producing, for example, Golfs, Audis, New Beetles, Skodas and Seats off similar platforms while managing to give each car its own character. You could even say VW pioneered the concept with the Beetle, which lent its floor, suspension, and engine to the Transporter van and Karmann-Ghia coupe. Ford plays this game, too, with the Focus and Mazda3, for example, and, though purists are upset by this, the Jaguar S-Type and Lincoln LS. General Motors has long used the platform system, most notably with the Buick Regal, Pontiac Grand Prix and Oldsmobile Cutlass.
Thanks to GM we can now show you the real thing during its development phase (photo above). This is a brand new platform known as "Kappa," which had its origins in the Pontiac Solstice concept of two years ago. In order to make a business case for the huge cost of developing the Solstice, an inexpensive, low volume (by GM standards) 2-seat sports car, the company decided to create a platform that could be used for at least three -- and possibly more -- vehicles.
The Kappa was revealed in media presentations at the 2004 Detroit Auto Show, actually driven onto the stage as a Solstice development mule by GM's car czar Bob Lutz. He then proceeded to startle and amaze the 6500 assembled journalists by unveiling two more cars to be built on the same platform, one by America's Saturn, the other from England's Vauxhall.
As most everyone knows, the auto world is changing fast, driven by computer-based technology and mergers or buy-outs. The market is being carved into niches in an effort to create distinctive vehicles that meet a wide variety of consumer needs. Platform engineering plays a huge role, cutting costs and speeding development time, giving us a sometimes overwhelming choice of buying options.
We wouldn't have it any other way.
