Chrysler Corp.'s re-engineered 1996 minivans face some formidable opposition that, until quite recently, has been lacking. But catching the overwhelmingly successful market leader won't be easy.

The idea of a using front-drive technology to build a very passenger-friendly, garageable small van had been kicking around for years. But Chrysler, its future uncertain in the early 1980s, nevertheless moved ahead and introduced the first of the new breed in 1984.

General Motors Corp. and Ford Motor Co., meanwhile, were developing minivans. Unlike Chrysler, which applied passenger-car technology to develop what became a new class of vehicles, the Big Two chose rear-drive truck technology.

GM's Astro and Safari minivans, and Ford's Aerostar, joined the minivan parade in 1985 and are still being produced. Because they chose rear-drive powertrains carried over from their light-truck lines, they were forced to accommodate a driveline to the rear wheels. The minivans thus stood taller and were more truck-like than Chrysler's lower-riding front-drive models using the front-drive K-car drivetrain and featuring a low step-in height and low beltline for excellent visibility.

The GM and Ford RWD minivans can haul heavier loads - more than twice that of the Chrysler minivans - but they gave up packaging efficiencies that became the benchmarks as Chrysler's minivans gathered momentum.

GM made a stab at Chrysler's territory when it introduced the APV line of plastic-skinned front-drive minivans in 1990, using the GM A-body midsize car platform as the starting point. The APV's radical styling has never really caught on, however, and it'll soon fade away.

Next year GM will introduce a new line of minivans developed jointly with its Adam Opel AG subsidiary in Germany. Eyeballing a photograph of the '96 Dodge Caravan, a GM designer exclaims: "That looks just like ours!"

Despite Chrysler's success, it was not until 10 years later that a U.S.-designed minivan coming close to its layout reached the market. Ford's Windstar, which to the untrained eye looks remarkably like a stretched version of Chrysler's all-new '96 minivans, finally put Ford close to parity when it bowed in 1994.

The Japanese didn't rush to grab Chrysler's coattails. And when they did move, only Nissan Motor Co. Ltd. chose to adopt Chrysler's basic architecture. The front-drive Nissan Quest and sister Mercury Villager, built since 1992 by Ford in a joint venture with Nissan in Ohio and engineered by the Japanese automaker, arguably are more refined versions of the original Chrysler design.

Toyota Motor Corp. and Mazda Motor Corp., meanwhile, selected rear-drive configurations when their entries debuted in the early '90s. They are excellent vehicles, but somewhat out of the mainstream, at least as defined by the market leader. Honda Motor Co.'s recently introduced Odyssey has received widespread plaudits, but it's considerably smaller.

Although they may not have known it then, the engineers and designers who developed the original "T-115" minivan 15 years ago were to become pioneers in what has become an obsession with vehicle space-packaging at Chrysler.

President Bob Lutz, no slouch himself when it comes to packaging, gives much of the credit to his top engineering lieutenant, Vice President-Vehicle Engineering Francois Castaing. He describes the former French race driver and Renault engineer "as the best packager I've ever known."

I recently asked Mr. Castaing his views on the engineering philosophy behind the 1996 minivan makeover. "We believe packaging is a science most people do not understand," he says. "It's the science of offering a lot of space and usable utility within (a given) exterior envelope. Our goal is to carve a better `home' for customers. It's like two architects who are asked to build a home on the same lot within the same budget. One will give you more space and more room for your money than the other."

It starts with defining and designing the interior, he says, which is the philosophy that led to cab-forward" and generous space for passengers. As a result, the short-wheelbase version of the '96 minivan is 3.6 inches (9 cm) shorter than Ford's '94 offering, yet has 13% more cargo space.

Chrysler executives are puzzled why, given their minivan miracle, that competitors have waited so long to produce clones. Maybe it's because they've yet to fully grasp the artful science of vehicle packaging.