As the century draws to a close, it's remarkable to ponder the advances and evolution in all aspects of society.

Influenza, which once claimed as many lives as both world wars, is not the public health threat it once was. Smallpox is on the brink of eradication. American women and minorities won the right to vote. Einstein gave us the theory of relativity. A man walked on the moon.

Yet in the face of such dramatic change, the materials used to build automobiles, an industry in its infancy at the turn of the century, are essentially the same.

Real wood is still used to dress up interiors in luxury cars. No one's come up with a better material for tires than rubber. Glass has yet to give way to polycarbonate windows. Although its eight-year ascent has ended, steel remains the most popular automotive material and has been refined to compete more with aluminum and plastic. Although it has lost ground, iron remains the predominant material for engine blocks. In fact, the iron content in an average U.S.-built vehicle still weighs in heavier than an NFL lineman.

So it's not all "space-age polymers" and electronics that drive the auto industry, but the tried and true commodities employed by Henry Ford and Gottlieb Daimler.

Sure, lightweight plastic will compete with steel, most recently in the area of pickup truck beds (see story, p.63). And the big gainer, aluminum, as well as even lighter magnesium will compete with iron and steel. But no one is predicting that any of these materials will go away completely in the near future.

The new vehicles for the 2000 model year illustrate this point, as they are loaded with innovative first-time applications for many materials. We'll show you some of them in the folowing pages.

For the past eight years, steel use has been rising because of the increasing popularity of steel-intensive sport/utility vehicles and pickup trucks, the up-sizing of most cars, and the general beefing up of vehicle body structures to make them stronger and stiffer for safety and handling improvements.

The continued introduction of big steel-intensive "light" trucks such as the new 8,000-lb. (3,600-kg) Ford Excursion and the upcoming crossover BMW X5 ensure steel will remain the dominant automotive material for the foreseeable future. In fact, the total amount of steel used per vehicle has dramatically increased from about 1,660 lbs. (753 kg) in 1991 to almost 1,800 lbs. (816 kg) in 2000.

But after steadily gaining ground throughout the 1990s, steel use in the typical family vehicle will drop about 15 lbs. (7 kg) on a per unit basis, American Metal Market reports.

For the 2000 model year, lightweight alternative materials look like they're finally making a dent in steel's dominance, albeit a small one.

Despite the perception that aluminum, plastic, magnesium and other materials are rapidly displacing steel, the percentage in a typical family vehicle dropped only 5% from 1976 to 1999. Now for the 2000 model year it's dropped another 1% to 54%.

But steel quietly has won back some high-profile applications that were made from - or originally slated to be - other materials.

One significant change the steel industry is gloating over is the decklid on Ford Motor Co.'s 2000 Taurus, which will be made of galvanized sheet steel. The decklid on the previous-generation Taurus was aluminum, says Marcel van Schaik, manager, advanced materials at the American Iron and Steel Institute.

In addition, hoods on the '99 Jaguar S-Type were switched from aluminum sheet to galvanized sheet prior to launch, and the new "plastic bodied" midsize Saturn L-Series also has a roof, hood, decklid and rear fenders made of steel, Mr. van Schaik says.

The steel industry also is making progress with new processes such as tailor welded blanks (for body side inners in the '00 GM G-body cars and full-size SUVs), and hydroforming (front frame rails and cross members in the '99 GMC full-size pickups, side rails in the '99 Corvette and roof rails in the '99 Buick Park Ave.)

The industry continues developing stronger grades of steel, which can be formed into lighter components and structures, thus reducing its own poundage. But that's okay with steelmakers because lighter, stronger grades of steel are more profitable and more competitive.

Steel folks can brag all they want about replacing lighter alternative materials in some automotive uses, but the arrival of plastic pickup truck beds is the equivalent of a grand slam for the plastics industry.

"A pickup bed is a terrible application in steel," says Jim Best, project director for the Automotive Plastics Report, published by Market Search Inc. He recalls General Motors Corp. talking about the possibility of plastic pickup beds in the 1960s.

"The bed takes tremendous punishment. You dump 55-gallon drums in it, you scrape the paint, then you put corrosive things in there," Mr. Best says. "The combination makes steel rust out so bad that putting in a liner has become common practice."

Elsewhere, Mr. Best sees strong markets for plastics underhood, with glass-reinforced nylon intake manifolds. The fuel tank market will continue migrating toward polyethylene as layers are added to prevent vapor leakage.

Overall, plastics content on the average North American vehicle is expected to climb from 253 lbs. (115 kg) in 1998 to 299 lbs. (136 kg) in 2008, according to Market Search. AMM, which charts all automotive materials, says plastics and composites content has stabilized around an average 245 lbs. (111 kg) per vehicle since 1992.

GE Plastics has tapped what could become a lucrative market in headlamp reflectors. Years ago, they were made of steel and, more recently, bulk molding compound (BMC). But BMC can be brittle and difficult to handle, in addition to requiring secondary operations, such as metallic coating.

GE Plastics' solution is Ultem, a thermoplastic made from a high-performance amorphous resin. Currently, the material is being used for headlamp reflectors on the Lincoln Town Car.

But nine additional vehicles are launching in North America with thermoplastic reflectors for the 2000 model year, including the Ford Focus, and another nine vehicles will launch shortly after that, says Jim Wilson, technical manager of advanced components and lighting for GE Plastics. The savings amount to $1 per headlamp.

DuPont Zytel nylon resin is used for the plastic pedal bracket for Europe's new Rover 75, the first volume production sedan so equipped. The component weighs about a third less than the metal it replaces.

Cambridge Industries says it will be the first molder in North America to use flax polypropylene, a recyclable and strong natural-fiber-reinforced substrate, in an automotive interior. It will manufacture the rearshelf trim panel for the 2000 Chevrolet Impala.

And the center console of the sporty Audi TT demonstrates a successful blending of plastics and aluminum. The console is made of Lustran thermoplastic from Bayer AG, and a simple clip system creates a firm bond with the aluminum facings of the radio and ventilation nozzles.

It's too early to say exactly what it means to automotive, but the recent three-way merger between Alcan Aluminum Corp. of Canada, Pechiney of France and Algroup of Switzerland appears to have spurred on a second blockbuster aluminum merger.

After launching a hostile takeover, No.1 aluminum producer Alcoa Inc. reaches an agreement to acquire No.3 Reynolds Metals Co. for $4.3 billion in an all-stock transaction. Reynolds has until mid-September to seek a better deal.

Reducing competition could result in higher aluminum prices for carmakers. Then again, prices could remain stable or actually go down if the consolidations result in significant improvements in efficiency.

Meanwhile, aluminum continues to expand its role in automotive production, led by new high-visibility applications on Ford Motor Co.'s Lincoln LS sport sedan and General Motors Corp.'s redesigned SUVs. Aluminum is rated by most industry sources as the fastest growing automotive material.

AMM predicts use of aluminum by North American automakers will rise to 246 or 248 lbs. (112 or 113 kg) per vehicle during the 2000 model year, an increase of 10 to 12 lbs. (4.5 to 5.4 kg) over last year. That represents a 4% gain in unit content over 1999.

The Volkswagen AG Lupo recently debuted in Europe sporting a mostly aluminum 1.2L engine and doors and hood made of the light metal. The Lupo is claimed to be the first production car capable of consuming only 3L of diesel fuel per 100 km (78 mpg).

But in the U.S. aluminum continues to make most of its gains at the expense of cast iron - not steel - as the trend toward aluminum engine blocks, heads and suspension components continues on numerous high-volume engines, including the cylinder block, head, bedplate and oil pan on Saturn's new 2.2L 4-cyl. engine for its L-Series cars, the blocks and heads on Toyota's U.S.-built 4-cyl. engines and the blocks and heads of the new V-8 engines for Lincoln's LS model.

The aluminum fenders on the Lincoln LS are the first in decades used on a relatively high volume car. The LS also features aluminum hood, decklid, suspension control arms, steering knuckles, differential carriers and chassis crossmembers.

GM introduces aluminum liftgates on its redesigned Suburban, Tahoe and Yukon SUVs. The liftgates are estimated to use about 25 lbs. (11 kg) of the light metal, replacing steel.

Production is being boosted on several major aluminum-intensive engines, including Honda V-6 engines, Ford Triton V-8 engines and DaimlerChrysler 4.7L aluminum head truck engines.

In the future, GM reportedly is considering manufacturing aluminum-intensive SUV's, possibly building on the expertise of its new business partner AM General, which makes the Hummer.

BMW AG's Rover SUVs already have aluminum-intensive bodies, and Ford is rumored to be developing an aluminum-bodied crossover vehicle. At the Frankfurt auto show this month, BMW introduces the production version of its all-out roadster, the Z8, which has extensive aluminum, including space frame and removable hardtop.

Other new aluminum parts on 2000 models include the engine cradles on the new Chevrolet Impala and Monte Carlo, roof racks on Nissan Xterra SUV, and hoods on Cadillac DeVille, Buick LeSabre and Pontiac Bonneville.

Easy to mold and significantly lighter than even lightweight aluminum, magnesium continues to make big inroads in the 2000 model year as automakers focus increasingly on making lighter, more fuel-efficient vehicles.

Globally, automakers such as Volkswagen AG and DaimlerChrysler are employing magnesium to shave pounds off everything from tiny minicars such the VW Lupo to the stratospherically priced Mercedes CL coupe, which features the world's first die-cast magnesium door inner panels.

In coming years North American automakers will turn increasingly to magnesium to lighten up heavy high-volume SUVs such as the Ford Expedition and Explorer and beefy cars such as the 2000 Cadillac DeVille.

Industry sources say Ford - which during 1996 and '97 switched a number of magnesium parts such as light truck transfer cases to aluminum for cost reasons - now is planning to change many of those applications back to magnesium in order to chop weight. It's also expected to start using big, full-length instrument panel support beams made from magnesium on its SUVs beginning around the 2001 model year, first on the Expedition and then on compact Explorers. It reportedly beat out hydroformed steel tubing, plastic and aluminum beams.

Ford also is reportedly getting set to switch most of its plastic and aluminum valve covers to magnesium as well.

American Metal Market reports that for the 2000 model year, magnesium use rose to 8 lbs. (3.6 kg) per car, about 1 lb. (0.45 kg) more than last year, representing a 13% increase. That's thanks mostly to big increases at GM.

Two-piece full-width IP supports on the 2000 DeVille are one of the most significant applications of magnesium for the new model year because they are big and high-volume components. Furthermore, their two-piece design allows them to be molded in smaller die-casting machines, opening up the magnesium IP market to more suppliers.

VW, Audi, and other European automakers also are developing magnesium inner door frames, engine cylinder blocks, hoods, and body pillars.

Other significant magnesium components for the 2000 model year include the steering column supports on DaimlerChrysler Neon and one-piece IP support beams on Buick LeSabre, Pontiac Bonneville and Chevrolet Impala and Monte Carlo.

A flurry of new powertrains promises to give powder metals a boost in 2000 as they work their way into a growing array of engine and transmission parts.

P/M parts are formed by pouring fine metal particles the thickness of a human hair into molds and then subjecting them to intense pressure and heat in a press. The process creates strong complex-shaped components that require little or no machining.

Even though material costs are higher than making parts by more traditional processes such as casting and forging, the elimination of machining steps has become very attractive to automakers for parts such as connecting rods, gears, timing sprockets, pulleys, oil pump parts, camshaft lobes, main engine camshaft bearing caps and numerous other parts.

P/M usage in model year 2000 cars and trucks jumps more than 1.5 lbs. (0.7 kg) - to 36.5 lbs. (17 kg), AMM reports.

New V-8 and V-6 engines and transmissions being introduced for Ford Motor Co.'s new Lincoln LS, Toyota Motor Corp.'s 4-cyl. being built in Virginia, Saturn Corp.'s 2.2L L850 4 cyl. engines and a new line of automatic transmissions developed by Ford and Mazda Motor Co. Ltd. for use in its subcompact Focus cars all boast many new P/M parts. But AMM reports that P/M parts stealing applications from iron castings and steel parts on established engines and transmissions is driving growth more than applications on new drivetrains.

Donald G. White, executive director of the Metal Powder Industries Federation, expects P/M applications to grow about 6% annually. General Motors Corp., Ford and DaimlerChrysler AG all are bullish on the technology, he says.

GM's 4T80E transmission for high-output engines in front-drive cars contains 26.1 lbs. (12 kg) of P/M parts, the most of any GM transmission, Mr. White says. GM's small block V-8 used in Corvette and GM's F-cars, as well as the Holden Caprice and Commodore, Opel Omega and C/K pickups and vans uses 30.3 lbs. (14 kg) of P/M parts.

Ford is still on track to reach 50 lbs. (23 kg) of P/M parts in larger cars and trucks by the 2001 model year, including the Lincoln Town Car and F-Series trucks.

Chrysler's most P/M intensive engine is the 2.7L, which contains 25 lbs. (11 kg) of P/M parts.

Almost 1 million more engines will be built in North America with P/M connecting rods in 2000 than were produced in 1999, AMM reports. Some of those engines include GM's L850 I-4 and V-6 engines, the Lincoln LS V-6 engines, GM's Gen III Vortec V-8s, Ford's Triton V-8s and DC's 2.7L V-6s and 4.7L V-8s.

Other significant applications include:

n Exhaust system flanges and sensor bosses in Ford's redesigned Taurus/Sable and GM's Gen III V-8 engines on its big SUVs.

n Chain drive sprockets in DC's 45RFE rear-drive automatics.

n Camshaft lobes in Ford's Triton truck V-8s and DC's 4.7L truck V-8s.