Why can't you be more like your brother?" SID and EuroSID have heard it all their lives, and it has driven them apart. Everyone was hoping they'd be identical twins, but it never happened.

SID, the elder of the two, was born in America and was initially the focus of all the attention. But then EuroSID was born overseas. He was younger, smarter and more sophisticated. Many seemed to like him better, and SID hated him for it.

Then BioSID was born at General Motors Corp. in the U.S. He's smarter and more sophisticated than both, but still too young to be taken seriously in global politics.

And global politics is what this story is all about.

SID is short for side-impact dummy and EuroSID is his European brother. Actually EuroSID is more like SID's half-brother because the two often behave very differently in exactly the same situations.

That's not good when you're trying to design a car that will protect them equally well in a side-impact crash.

Do you use side air bags or less-expensive plastic foam padding? If you use side air bags, exactly when during the crash sequence should they deploy? How fast should they deploy? If you use padding, how much is appropriate, and where should it be located to give the most protection? How dense should it be? Should side air bags and padding be used together?

These are only a few of the questions engineers must answer when developing a vehicle that will meet side-impact standards. When two crash test dummies give different answers, compromises are impossible to avoid. Inevitably, engineers will err on the side of caution, in most cases causing the overall solution to be more costly than it should be. Yet the new vehicle probably won't provide optimum protection for either SID or EuroSID because the design was compromised to accommodate the idiosyncrasies of both. Is that smart engineering?

These two dummies, developed separately in the U.S. and Europe, are at the forefront of an effort by the U.S. Big Three automakers to "harmonize" global safety and engineering standards. The American Automobile Manufacturers Assn. (AAMA), representing GM, Ford Motor Co. and Chrysler Corp. petitioned the National Highway Traffic Administration (NHTSA) late last December to begin investigating standardization of side-impact dummies. AAMA also is pushing for the standardization of a handful of relatively simple tests relating to components such as windshield washer systems.

U.S. automakers are hoping the trade groups representing European and Japanese automakers, the Association des Constructeurs Europeens d'Automobiles and the Japanese Automobile Manufacturers Assn., will soon make similar petitions to their respective governments.

"There has been a very tortured history here where it took between 10 and 20 years to develop an international brake standard. That is now an unacceptable time frame," says Vann Wilber, director of Vehicle Safety and International Affairs at AAMA. "This is much more aggressive."

What AAMA is proposing is that the U.S., Europe and Japan (Japan typically uses Europe's safety and engineering standards) recognize U.S. and European side-impact dummies as "equivalent" and eliminate separate, redundant tests for each. This could then lay the groundwork for the eventual adoption of one standardized SID dummy in the future.

A possible scenario would be to first have the two dummies coexist with separate-but-equal status: Europe recognizes a test with U.S. SID as equal to EuroSID and vice versa. Then EuroSID would be acknowledged as more advanced, and he would become the global standard while auto-producing nations then collaborated to develop an even more sophisticated universal SID, perhaps along the lines of BioSID. (BioSID currently is used widely as a development tool, but isn't a part of formalized government testing standards.)

It is the first step in an overall global standardization effort that could save the world's automakers untold billions and countless engineering man-hours every year. Some experts estimate the cost of complying with all international crash standards now can add 10% to a new vehicle's sticker price. That doesn't include the multitude of other compliance tests analyzing such things as headlight beam patterns and how windshield washers work.

Elizabeth Brueckner, executive director of the United States Council for Automotive Research (USCAR), the umbrella organization for joint Big Three research and development consortia, calls it "strategic standardization."

"Strategic Standardization Management, as adopted by Polaroid, Motorola, Hewlett-Packard, United Technologies, Ameritech and others, means developing policies on standardization that add customer value and make each company more competitive, especially on an international scale. Each of our companies needs to recognize the increasing importance of actively, not passively, managing the relationship between standards, conformity assessment and international trade. The fact is, standards define the rules of international trade."

In theory, all automakers are in favor of the idea.

But standing in the way are daunting international politics, plus differences in cultures and driving habits that affect everything from air bag deployment speeds to what kind of headlight bulbs are used.

Arcane, highly specific standards - especially those supposedly related to safety - often are used as effective and politically unassailable trade barriers, industry sources say. That means many of these standards won't be given up easily.

Furthermore, just standardizing GM, Ford and Chrysler's cigarette lighters from over 30 designs to four was a monumental undertaking that was completed only recently by USCAR. Imagine how difficult it would be to standardize safety or other standards throughout the world among all automakers.

George English, director of Lighting Systems at Osram Sylvania, says it can take 3 1/2 years just to get a new light bulb design approved in Europe. He adds that required headlight beam patterns can vary greatly from country to country. U.S. drivers, for instance, expect headlights to illuminate virtually all street signs, while a high percentage of signs in Europe have their own lighting. U.S. customers also expect vehicle lights to last longer than Europeans. The latter typically are more demanding about lighting performance. These are conflicting demands that aren't easily reconciled, Mr. English points out. But he adds that tailoring a U.S. model's headlights and optics to meet various European standards can easily cost an automaker several million dollars.

Crash standards are infinitely more complicated, and introduce far more variables. For instance, in the U.S. there must be tests for both belted and unbelted occupants in a full-frontal collision with a fixed barrier. In Europe, there is no unbelted test because almost everyone wears belts. There are very stiff penalties for those who don't. However, Europeans insist all cars pass a test where vehicles crash into another car or partially offset barrier. This offset crash is believed by the European community to be a better test of the integrity of a vehicle's body structure, and more accurately represent real-world crashes.

Proponents of the U.S. barrier crash say it's superior because it represents the most violent type of deceleration a driver or passenger can face - and that's the best way to test the efficacy of air bags. However, NHTSA is developing an offset frontal crash test of its own. Unfortunately, it will likely be different from the European offset test. That could amount to a fourth test and add more complexity to engineering a global vehicle.

What's wrong with engineering for three or four different kinds of frontal crash tests? Besides the additional time and engineering costs involved - which are enormous - one expert points out that designing U.S. cars to meet a European-style offset barrier crash means the front corners of the vehicle body or chassis must be made stiffer. That changes how the body absorbs crash energy during the current U.S. full frontal test: It won't be as "soft." Engineers have to compensate for this by increasing air bag deployment speeds, and that raises the risk for air bag injuries.

Such injuries aren't a big issue overseas because they seldom occur with belted drivers or passengers, and those who don't wear belts get little sympathy. In the U.S., of course, almost a third of drivers don't wear belts, and anyone injured by an air bag is considered national news.

There are hundreds - or thousands - of other variables as well that can have an effect on how safety systems operate and standards are developed. Americans generally tend to sit closer to the steering wheel when they drive; Germans like to sit far away, with arms extended, for instance.

Another big cultural difference is vehicle weight, points out Charles E. Steffens - director, systems application engineering at TRW Occupant Restraint Systems. Because of the popularity of light trucks in the U.S., the average U.S. vehicle probably weighs 1,000 lbs. (454 kg) more than typical vehicles in Europe or Japan. The mix of vehicles also is substantially different in each country, he adds, as is the attitude of government regulators regarding car/truck crashes.

Accommodating many of the differences between European and U.S. safety standards is not terribly difficult with today's sophisticated, electronically controlled safety and air bag systems, says Kenneth Francis, North America program director, safety and chassis systems for Siemens Automotive. In many cases it's only a matter of changing software. Tomorrow's smart, highly adaptable air bag systems also may solve some of the problems of meeting differing global safety standards, but they will not be a panacea, he emphasizes.

Given all these complexities, no one is expecting harmonization to come quickly, but AAMA's Mr. Wilber points out that the first step of simply allowing SID and EuroSID to coexist is not a huge leap in political terms. After all, these are just a couple of dummies, not Cain and Abel.