Chrysler's Prowler: more than a material showcase, it's a real product

Anyone wondering why Chrysler Corp. has some of the world's lowest product-development costs should visit their local Plymouth showroom early next year. Sitting there, briefly, in a few lucky dealerships, will be one of the more technologically impressive production vehicles to come along in some time.

Even if you hate its retro-style looks, pull your nose up at its mundane 3.5L engine, and sneer at Chrysler's low-cost "let's use only off-the-shelf components from our parts bin" development strategy. No matter what, the Plymouth Prowler is a heck of a showcase for lightweight materials technology, including:

* A lightweight aluminum body structure with full-perimeter frame made of aluminum castings and extrusions and featuring innovative self-piercing rivet and adhesive bonding techniques for critical joints.

* Body panels made of a brand-new 6022 aluminum alloy that breaks new ground in strength and formability.

* Other body panels made of a new SMC (sheet molding composite) that is lighter and more flexible than conventional SMC material.

* Aluminum suspension components made with a new semi-solid forging process that produces engineering properties formerly unheard of for such parts.

* A giant magnesium instrument panel support structure that not only saves weight but consolidates parts and cuts assembly costs.

* Aluminum composite brake rotors that are half the weight of conventional cast iron.

Granted, most automakers are working on experimental lightweight vehicle development programs, but the Prowler -- thanks to heavy technological commitments from suppliers -- is a materials showcase with a difference: It actually will be sold in the marketplace, and quite possibly at a profit.

Coming to Plymouth showrooms in the first quarter of 1997, it has a 5,000-unit plus annual production volume and a semi-affordable sticker of about $35,000. Total program cost: about $75 million. In the world of automotive new-product development, that's postage stamp money. Not bad for a company that less than two years ago was criticized for being too lean and lacking adequate research and development capabilities.

That's not to say other automakers don't have interesting materials projects under way. The Big Three all are contributing significant resources to the Partnership for a New Generation of Vehicles (PNGV), a joint research project between the U.S. federal government and their USCAR technology consortium. It's aimed at bringing a Taurus-size family car to market early in the next century that gets triple the fuel economy of today.

What's more, Ford Motor Co. has its aluminum intensive vehicle (AIV) program, a $25 million fleet of 20 aluminum-bodied Sables, plus aluminum-bodied Synthesis and Synergy concept cars. But you can't buy them. General Motors Corp. has its new EV1 electric car, a lightweight technological tour-de-force with an aluminum body structure that goes on sale this year. You can buy one of those for $30,000 pr so, but GM says it will never make a dime of profit on the car.

There also are light-weight, aluminum-intensive products available from Japanese and European automakers, such as the almost-extinct Acura NSX, the Audi AG A8 and the Lotus Elise -- but they are very low volume, very expensive -- or both.

Of course, aluminum-bodied Rover sport/utility vehicles are made in substantial numbers, but they aren't the least bit lightweight. Neither is the aluminum-bodied Hummer. That pretty much leaves the Prowler crouching alone in the realm of real-world aluminum-intensive production vehicles.

Among the most interesting elements of its lightweight strategy is that much of its materials technology has been directly transferred from Chrysler's Neon Lite program, unveiled 18 months ago. The program focused on using advanced -- but semi-practical -- alternative materials to chop the Neon's weight by 600 lbs. (272 kg) and improve fuel economy by about 5 mpg. High-priced exotic materials that clearly couldn't be put into production cost effectively -- such as carbon fiber composites -- were ignored.

That translated into using magnesium, glass-reinforced composites, and lots of aluminum. Francois J. Castaing, Chrysler's vice president of vehicle engineering, said then that the automaker would never introduce an all-aluminum Neon because it would be too expensive, and consumers wouldn't be interested in paying 20% to 25% simply for lighter weight.

However, he did say what was learned would be transferred to "future vehicle programs." He practically mouthed the word "Prowler."

In fact, some engineers at a press event unveiling the Neon Lite found themselves yanking business cards out of journalists' hands because they accidentally gave them new ones featuring Prowler titles -- and a picture of the car.

Saad M. Abouzahr was one such engineer. He supervised materials development on the Neon Lite, and then moved directly from that position to become materials executive on the Prowler program. He says the new car's innovative magnesium instrument panel support structure, aluminum bonding technology and aluminum composite brakes all came directly from Neon Lite research.

However, taking these new technologies and actually putting them into production takes the challenge to a new level. For instance, it was one thing to determine that self-piercing rivets combined with heat-cured adhesives provide the strongest, most cost-effective approach for bonding critical joints in aluminum body structures. It was quite another to actually devise a production system to do such joints, even for Prowler's relatively low volume.

But just as the Neon Lite provided a technological foundation for the Prowler, what is being learned now in Prowler production could lead to innovations on much higher-volume, mainstream vehicles in the future, Mr. Abouzahr says.

Some of Prowler's most significant materials innovations:

* Aluminum supplier Alcoa developed a new high-strength 6022 aluminum alloy for Prowler body panels that hits new levels in strength and formability, Mr. Abouzahr says. A heat-treatable alloy, the aluminum sheet is initially soft and formable, but after it runs through the high heat of the paint bake ovens used to cure automotive paint jobs, it becomes very strong and stiff, like a bake-hardenable steel. This material surpasses other special aluminum body panel alloys such as 6111, which offers good strength, but is not as formable, Mr. Abouzahr says.

* Key aluminum suspension components such as control arms are created using a new semi-solid forging process that makes them stronger, tougher and closer to the desired net shape. In a process similar to plastic injection molding, small billets of aluminum are heated until they are soft as butter and then put into a die. The process changes the texture and microstructure of the aluminum. "We're getting properties you've never heard of getting," Mr. Abouzahr says.

* The Prowler team also broke new ground in the way aluminum is supplied. The light metal has two key drawbacks for automakers, it costs three to four times as much as steel, and its price historically is very volatile because it is traded on world markets as a commodity "like pork bellies," critics often say. The Prowler team addressed the latter issue by negotiating a long-term pricing arrangement with aluminum suppliers to protect against major price fluctuations.