Chrysler Corp. dazzles television viewers with flashy computer graphics in its advertising campaign for the Dodge Intrepid, declaring that the car was designed digitally and tested in the "virtual world" until it was "virtually perfect."

Meanwhile, Chrysler and other automakers are struggling to let go of the traditional tools used for physical testing of new products. They are building new wind tunnels, upgrading their proving grounds and continuing to spend considerable time running prototypes through the rigors of Arizona and Minnesota.

Are automakers suffering from a bad case of indecision, or will it just take more time before computer simulations dominate the product development process?

While automakers stand at a crossroads between the real world and the virtual world, they appear eager to not only keep both roads open, but to cultivate an environment where they can travel both simultaneously.

Granted, rapid advances in computer software have provided engineers with innovative tools to mathematically simulate crash tests, vehicle dynamics, powertrain and brake performance, as well as the manufacturing process. Trial and error in cyberspace can eliminate design flaws before the first physical part is built, and every day shaved from product development saves automakers an estimated $1.5 million.1

The number of necessary prototype vehicles has declined steadily over the years with the help of these tools. Still, no one is declaring that the industry will soon eliminate - only reduce - the need to build and physically test products. At $1 billion or more to launch a new vehicle, the investment justifies grabbing the wheel and stepping on the gas.

"We still need proving grounds. We have new materials coming where we still have to do durability tests that we can't totally predict," William Powers, vice president-research at Ford Motor Co., says in August at the University of Michigan Management Briefing Seminar in Traverse City, MI.

His fellow Traverse City panelist, Chris Theodore at Chrysler, agrees there's a future for proving grounds. "But we're going to drive more and more testing into laboratories, into a more controlled environment so there will be in fact less and less testing being done on the roads," says Mr. Theodore, vice president-platform engineering.

Ironically, some suggest that these seemingly divergent approaches to validation stand to complement, rather than threaten, each other: Virtual testing has saved so much time that it allows more time for real-life testing.

Chrysler actually built more prototypes for its new large car platform (82, compared to 44 in first-generation large cars in 1993), including Intrepid, partly because of additional body styles and engine options and the need for more validation. Still, with new design tools, the job was finished in 31 months, compared to 39 months in 1993.

Among suppliers, two companies representing each side have formed a partnership that illustrates the need for both.

Instron Schenck Testing Systems, a maker of equipment for physical testing, has linked up with Leuven Measurement & Systems Intl., a computer modeling supplier, to market hardware and software for durability testing and simulation. The idea is to get each company's data base programs to communicate with each other.

"The two of us together should deliver more than either of us could apart," says Mike DeLeeuw, IST's vice president-sales and marketing.

But for the fledgling simulation industry, it's only a matter of time before every physical test can be done digitally.

"I'm absolutely convinced that will happen," says Mats Johansson, president of simulation software supplier Prosolvia Inc. "But if it's 15 or 50 years from now, that remains to be seen."

Engineering Technology Associates Inc. of Madison Heights, MI, has launched its Virtual Proving Ground software to simulate all road conditions, including potholes, cobblestone and washboard surfaces, and provide analytical results for durability and vehicle dynamics.

ETA President Abraham Keisoglou estimates the system, at a cost of $22,000 a year, can cut six to nine months from vehicle development.

Despite the proliferation of tools, one thing engineers have struggled to model digitally is wind flow around a vehicle. Hence the new construction of wind tunnels.

But at the component level, UT Automotive has managed to digitally replicate wind flow through automotive engine cooling fans the company builds. The technology was honed with the help of jet engine maker Pratt & Whitney, also a division of United Technologies Corp.

UTA used the Auto Fan system recently to develop and test an engine fan for PSA Peugeot Citroen, with two prototypes, in three months. The old system would have taken up to six months and eight prototypes, says Greg Tillman, senior research engineer at UT Research Center.

Although math-based testing is the rage, it isn't always the right solution.

"Sometimes we get obsessed with total math-based everything. But if you really looked under the covers you find it isn't always there," says Ralph Szygenda, chief information officer at General Motors Corp.

"Are we getting much better at math-based? Yes. Are we to the point of doing it all math-based? Yes," Mr. Szygenda says. "Is it economical and the right thing for cycle time? That's still debatable in some areas."