Public policy debates now affect every aspect of vehicle design, propulsion systems, and fuel usage. The scope and depth of these debates produced energetic discussions at two recent automotive conferences and led to some surprising questions.
For instance: How do U.S. drivers actually use their cars, and are government test cycles out of date? Does the United States require diesel engines to be too clean? Will the batteries developed for plug-in hybrids make regular old hybrids so affordable that plug-ins will never actually make sense? Could proposed European carbon regulations deal a mortal blow to the German auto industry? And how did London’s mayor inadvertently devastate the UK market for electric cars?
First, it turns out that Southern California drivers don’t drive the way the U.S. Environmental Protection Agency’s test procedures say they do. The EPA uses standard urban and highway driving cycles with patterns of acceleration, speed, braking, and idling that are now fairly well known to automotive regulatory engineers.
General Motors chose to use real-world driving data to model and benchmark its Chevrolet Volt extended-range electric vehicle, said Pete Savagian, director of engineering for GM hybrid power trains. He described a set of driving-cycle data, recently gathered from actual Southern California drivers in actual cars, to conferees at the Hybrid Vehicle Technologies Symposium, convened by the Society of Automotive Engineers (SAE) in San Diego in February.
What’s the bottom line? These drivers are tough on their cars—much tougher than the test drivers using the EPA’s regulatory cycles. And they drive very differently from the greenest of Toyota Prius drivers, who often attempt to keep their cars in electric mode as long as possible.
Why are these data significant? Like other sprawling suburban areas connected by freeways and six-lane arterials, Southern California lends itself to a rapid mix of high-speed driving and bursts of stop-and-go traffic—and its drivers are impatient. This pattern is much more reflective of how average U.S. drivers behave.
What, asked Savagian, was the median freeway speed based on actual Southern California driving data? The answer was 83 miles per hour (133 kilometers per hour). As Savagian remarked solemnly, ”Drivers in L.A. turned out to be very, ah, aggressive .”
As for diesel technologies, a panel at the Auto FutureTech Trade Fair—a new branded sub-track of the long-standing Globe Foundation conference on business and the environment, held in Vancouver in March—acknowledged that perhaps the biggest single issue for automakers is whether U.S. buyers will take to a new wave of ”clean diesel” vehicles over the next three years. Those engines will have far more complex and expensive emissions systems to meet U.S. limits on emissions of nitrous oxides (NOx) and particulate matter—the world’s most stringent guidelines.
More than half the cars sold in Europe are now diesels, but none of them are legal in the United States under the EPA’s Tier 2, Bin 5 restrictions. European makers see diesel’s greater efficiency as the obvious way to reduce both U.S. fuel consumption and global carbon emissions. And Europeans quietly pooh-pooh hybrid electric vehicles as expensive and needlessly complex.
But, asked one participant, can diesels ever hope to meet the ”super-ultralow” or ”partial zero” emissions levels already achieved by the Prius and even some nonhybrid gasoline cars? Timothy V. Johnson of Corning—a major producer of ceramics for diesel emissions controls—reminded the questioner that public health is now far more affected by particulate matter than the pollutants known as criteria emissions (nitrous oxides, carbon monoxide, and hydrocarbons). And, he said, a Prius now emits more particulates than the new clean diesels.