Walbro Corp., a supplier of fuel tanks and fuel delivery systems, filled up its own tank with $11 million in profit last year.

Over the past few years, the company has invested about the same amount to build several test chambers at its new engineering center in Auburn Hills, MI.

There's a cell for measuring NVH (noise, vibration and harshness) levels, one for heat testing, another to meet environmental standards and another highly secured chamber with a fuel pump inside to see just how well the company's fuel tank systems perform in real-life applications.

Next year, the company plans to shell out up to $2 million more for a cold test chamber.

A wise investment? Money managers might question the need to spend so much money to test products that offer such small profit margin. Company officials, however, are certain it was a smart move for the future, albeit a costly one.

Automakers expect a lot from suppliers these days, including the ability to fully validate a product before it reaches the final assembly line and before it causes warranty headaches.

At Walbro, the strategy was to build enough chambers not only for testing its products but to allow other suppliers to use the facilities if they had not yet invested in their own.

The gesture was not strictly humanitarian. Of course, the customer would pay to use the equipment, but the larger goal was to establish relationships with potential customers.

"A month ago, a company came in to use the facilities and they had a problem," says Michael Zdroik, Walbro's vice president of engineering. "We solved it, and in solving it, it generates a new product, and in the end it generates new business for us."

Until the Auburn Hills facility was built, Walbro was limited to smaller component testing at its facility in Caro, MI. Adding testing capabilities was an integral part of the company's move toward supplying entire fuel systems, rather than individual components. Today, the company has new business supplying systems for several vehicles, including the Dodge Durango.

Whether to make the enormous investment in testing is a question that suppliers must face if they want to become a systems player.

One supplier that opted to take that chance was Calsonic North America Inc. Its new headquarters in Farmington Hills, MI, is loaded with testing equipment, including a wind tunnel, five environmental chambers, an anechoic chamber and an electromagnetic capability chamber. The wind tunnel alone was a $5 million investment.

"Our customers tell us if we want new business, bring new technology to the table," says Ken Nelson, Calsonic's senior manager of marketing.

The tunnel cranks out wind of up to 100 mph (160 km/h) while simulating temperatures ranging from -22 degrees F to 122 degrees F (-30 degrees C to 50 degrees C) and humidity levels of up to 90%.

The equipment is used to test performance of Calsonic's heating, ventilation and air conditioning (HVAC) systems, as well as engine-cooling systems. Vehicles are equipped with a maze of thermocouple sensor wires, both underhood and in the passenger compartment, to check temperature levels, gauge airflow and evaluate overall product performance.

Testing is not new for Calsonic, but until now only components or systems could be evaluated in environmental chambers. The new wind tunnel is large enough to accommodate an entire vehicle, allowing for more complete testing.

"We've never had anything like this," says Arthur Naujock, Calsonic's manager of test and development engineering. "We've never had the ability to test a whole system inside a vehicle."

So why is it necessary to invest in real-life testing equipment when so much simulation can be done on computer? Mr. Naujock says Calsonic does some computer simulations, but the computing power is lacking and the technology needs further development.

"Few computer programs can simulate an air-conditioning system as it operates in a car," Mr. Naujock says. "You still have to test in real life because the computer is testing only what the programmer set it to do. But in real life, we have to satisfy 3 million to 4 million people."

Lori Cumming, director of General Motors Corp.'s Thermal HVAC Center, says the company is moving toward computer simulations but agrees that barriers remain. "You can't validate HVAC on a computer," she says.

Because of the computer shortcomings, GM is spending $50 million to renovate a hot test chamber and to build two new fully climatic wind tunnels - with a range of

-40 degrees F to 140 degrees F (-40 degrees C to 60 degrees C) - at its Technical Center in Warren, MI. The complex is slated for completion in early 1999.

GM's goal is to shave time and expense off its lengthy product-development cycles. "We'll be able to do this testing any time of year and not have to follow the weather," Ms. Cumming says. "It decouples us from the seasons."