AMSTERDAM - Almost all carmakers are cutting costs by reducing vehicle platforms. But not all of them agree on what a platform is.
Volkswagen says its Golf, Beetle and Audi A3 share a platform. BMW says the two- and four-door versions of its 3 series do not.
However a platform is defined, nearly every company wants fewer of them. Ford Motor Co. wants to go from 32 to 16 platforms by 2004. Nissan has 30 global platforms now and wants to reduce that to 10. Five years ago, VW decided to cut its 16 different platforms to just four.
Renault has five platforms now and wants just three in 2000. The Laguna, Safrane and Espace successors will all be based on one platform.
While cutting the total number, almost all companies want to spin more variants off each platform. That requires a more flexible substructure and a looser definition of the term.
A platform once meant the floorpan architecture, sometimes even with fixed door openings and front and rear window frames. It has a much broader meaning now, allowing for differences in wheelbase and even width.
Renault defines a platform as the engine bay, points for attaching the front suspension, and the central and rear floor sections.
For Nissan Europe President Norio Matsumura, a platform means a common engine bay and suspension system, but a floor section of flexible length.
Rudy Kunze, vehicle line executive at Ford of Europe, said cars with a common platform should share the same welding lines, suspension system and drivetrain.
Peter Hanenberger, head of General Motors Europe's technical development center in Germany, said the front engine compartment and the seat frame should be as common as possible.
'Volkswagen is really taking flexibility to the maximum extent,' said Kunze.
VW's idea of a platform includes: drivetrain; suspension; seat frames; and electrical, steering and fuel systems.
'Cars built off the same platform can have different widths or wheelbases,' said a VW spokesman.
Honda made news this year with its flexible Accord platform concept.
Honda says it can easily and cheaply vary the platform's width by changing brackets on the suspension subframes and a cross-car beam in the floorpan behind the B-pillar.
Fiat laid down a five-platform strategy in 1978, but platform architecture was more rigid then than now, said Nevio De Giusto, head of platform strategy.
Today, a platform can mean two things at Fiat.
'It could be either a chassis with common mechanical parts,' said De Giusto, 'or it could be a team or development organization.
'It is a platform,' he said, 'if you carry over 70 percent of the parts.'
Exterior and interior design flexibility is now considered critical. The hard points should not put too many restrictions on a designer. Volkswagen says its flexible concept allow for design freedom.
'The Golf looks completely different from the new Beetle,' said a VW spokesman, 'but they share the same platform.'
Common platforms allow uniform production processes, said Christian Dewulf, president of NedCar in Born, Netherlands. The joint venture builds the Volvo S40/V40 and Mitsubishi Carisma on a single line.
Eighty percent of production processes and 30 percent of parts are common between the two NedCar products.
'Process commonality is essential, otherwise you will create split personalities on the line,' he said. 'It could make both partners grow apart.'
An essential part of Dewulf's platform definition is that the mechanical components of each model should be attached to the body in the same way.
'A mix of front-wheel drive and rear-wheel drive models on a single assembly line goes beyond the common platform definition,' he said.
Ford makes the Puma sports coupe on the same assembly line as the Fiesta in Cologne, Germany, but performs specific Puma bodywork operations off line.
Even with a flexible definition, the savings are considerable when platforms are shared.
VW Chairman Ferdinand Piech has said that the group could save DM3 billion ($1.7 billion) per year on development and production costs when its four basic platforms are shared among VW, Skoda, Seat and Audi.
Fiat's De Giusto said development costs are lowered by 30-50 percent and tooling costs by 25 percent when a car comes off an existing platform. Ford calculates a saving of 15-20 percent on development costs and 15-20 percent on engineering costs.
Renault expects its platform strategy to cut FF1.5 billion ($250 million) a year from production costs.
Common platform strategies are not exclusive to high-volume producers.
Porsche's Boxster and new 911 share the same platform. Their front structures up to the B-pillar are identical.
But BMW says it does not believe in a common platform strategy.
'We are a premium niche model manufacturer,' said Hans Ratgeber, head of BMW body engineering. 'We focus more on customer needs than cost-saving volume production.'
BMW's 3 series has five variants: a two-door, four-door, Touring, Compact and Cabriolet. But BMW says that they are not based on one platform.
'Even if we apply similar body structures, and we work with certain symbioses between our own model ranges,' Ratgeber said, 'there remain principal differences.'