Back to Stories Overview

Powering the fight against global smog

Car traffic contributes greatly to climate change, but there's a more immediate problem: smog. In many major cities around the world, air pollution causes illness and shortens lives. But e-mobility can help reduce smog and improve the outlook of millions.


Los Angeles is a bustling hive of activity with the worst traffic in the United States. The average driver spends 80 hours each year sitting in traffic delays.

Evenings, the red and white glows of headlights and taillights from the 6 million commuters pave seemingly endless miles of freeways and local streets. Hovering above them, invisible in the cityscape-lit glow, though evident during days as someone comes into LA, is a different color. Brown haze envelopes the land. The City of Angels may be an entertainment capital, but it’s also a kingdom of smog. The pernicious form of pollution is the sunlight-fueled reaction of petrochemical emissions from vehicles and industrial plants. Layers of light warm air over a cooler and denser base creates an atmospheric inversion that traps the mix like a covered pot and makes it a constant companion to the people below.

Brutal levels of smog aren’t limited to Los Angeles. As bad or worse covers Tehran, Mexico City, Beijing, Moscow, and many other urban areas, whether in the Middle East, China, Southeast Asia, Europe, or the Americas —virtually anywhere with high population density.

Pollution takes a terrible toll on health. The World Health Organization estimates 80 percent of people living in cities that monitor air quality face conditions that exceed safety guidelines. Between 2008 and 2013, air pollution increased by 8 percent. Low- to middle-income countries have the worst quality air. More than 3 million premature deaths every year owe to pollution.

One big driver of pollution is traffic. Cars, taxis, and buses belching the byproducts of internal combustion engines create the fine particulate matter that becomes airborne and then enters the bodies of residents. What can make an enormous difference is a shift from internal combustion vehicles to e-mobility: electric cars, buses, and other forms of transportation. Government regulations around the world to combat climate change will increasingly make e-mobility a necessity.

However, a change in vehicle power source is beyond a simple swap of engines. Even if you could remove a conventional petroleum-powered unit and replace it with an electrical motor and battery, the vehicle would still need extensive redesign and reengineering. The drive train and gearing in electric vehicles have different requirements.

An e-vehicle might use braking to drive a generator that recharges the battery. Electric cars can provide smoother acceleration and offer instant power to address hills, so require different transmissions and gearing that conventional automobiles, says Siegfried Xu, Sales and BD Director, China for Oerlikon Drive Systems China.

“E-motors have a much higher max RPM than the conventional ones do,” Xu said. “This has a significant impact on gear design and gear manufacturing.”

Electric vehicles have had some weaknesses compared to conventional vehicles, particularly in the range of operation. But technology can help address the shortcomings. Oerlikon Graziano, for example, has a 4-speed electric drive that includes two drive shafts, each with its own electric motor. The design enables 15 percent greater overall efficiency, increasing the range of the car.

Making the change to e-mobility will require effort and investment. But over time, the green technologies will help wipe brown haze from the air and let people breathe freely again.

Oerlikon Graziano has 20 years of experience in developing e-mobility technology, from the first golf/utility transaxle to contemporary transfer cases that enable light commercial vehicles, including zero-emission city cars.

By Erik Sherman


No comments available

Be the first to write a comment about this article.

Leave a comment
Related stories