The automotive supply chain is filled with companies that want to bring systems capabilities underhood.

We've already heard about suppliers eager to provide single-source engine sealing packages, ready-to-install cylinder heads with complete valvetrains and more complex air intake systems with throttle bodies.

Why, then, should pistons be left out of the trend? They won't be for long.

Three leading piston suppliers, Mahle GmbH, Kolbenschmidt Pierburg AG and Federal-Mogul Corp., have been positioning themselves aggressively through acquisitions, mergers or new construction to bring piston systems to the auto industry.

One company may call it the "power cell" and another the "power cylinder," but the system is essentially the same, including piston, rings, pins, bearings and connecting rod. The cylinder liner also could be integrated. Piston systems can be lighter, less costly, more durable and easier to install than conventional assemblies.

This year, German-based Mahle will take a step toward its "power cell" system when it supplies the piston, pin, ring and connecting rod for a low-volume passenger car platform in North America for model-year '00, says Wolfgang Rein, senior director of product engineering at Mahle's new technology center in Farmington Hills, MI.

Mahle will purchase the connecting rod, but Mr. Rein says the company has plans to enter the connecting rod business through internal growth rather than through acquisition. It is not clear, however, whether this endeavor would entail production or machining of connecting rods, or both.

Kolbenschmidt Pierburg, also of Germany, stepped up its modular presence through its recent acquisition of Zollner Pistons, a smaller piston producer based in Fort Wayne, IN.

Sources say Zollner will supply the power cylinder for two North American light truck engines, one high volume and another low volume, in '00. Zollner will produce the piston and buy the other components.

Kolbenschmidt Pierburg (kolben is German for piston, by the way) has about 15% of the worldwide piston market and gains another 4% with Zollner. Still, it lags behind market leader Mahle, which sells about 25% of the world's pistons, based on industry estimates.

In North America, Zollner and Kolben-schmidt Pierburg will dominate the piston market, or be second largest behind Mahle, depending on whose market data you believe.

Federal-Mogul, through its acquisition of T&N plc, has about 12% of the world piston market, but that figure will grow by an estimated 5% with its recent acquisition of the piston operations of Alcan Aluminum Ltd.

But Federal-Mogul has something that Mahle and Kolbenschmidt Pierburg currently lack: the ability to machine connecting rods. That came with the recently completed acquisition of Tri-Way Machine Ltd. of Canada. Federal-Mogul, incidentally, had been in the connecting rod business until the mid 1990s, when new corporate strategy forced a sale.

All three companies have shown power cylinder systems to OEM customers, and interest is high.

Alan Johnson, executive vice president of powertrain systems at Federal-Mogul, says he expects his company's first system to appear around '03.

Given a clean sheet, Federal-Mogul - and others - say an OEM can save 10% or more in buying the system rather than the individual components.

How? By designing to take weight out of the head of the piston or the connecting rod, Mr. Johnson says.

As for weight savings, it might amount to only grams, but multiply that by six or eight cylinders and it adds up quickly, perhaps equaling another mile per gallon.

At Mahle, the first power cell prototypes are leaving the company's Morristown, TN, factory this spring, with full production coming this summer. The company is not saying how many units are expected in this first contract, but volumes are expected to bloom as vehicle manufacturers press for piston systems across many platforms.

Playing a key role in Mahle's development of the power cell is Mahle Technology Inc. (MTI), the new tech center in Farmington Hills that houses 70 employees providing design and engineering support for customers and other Mahle divisions in North America. MTI is one of four Mahle development centers worldwide.

MTI offers engine testing (diesel and gasoline), two engine dynamometers (with plans for four more), dimensional and failure analysis, stress measurements and numerical simulation of power component systems.

The $8.5 million building replaces a smaller facility Mahle operated in nearby Walled Lake, but its new site in Farmington Hills is hardly landlocked: Mahle can expand to the east, west or south if necessary.