A new way to save gas: drive more smoothly

"Eco-driving" is a technique that combines a racecar driver's skill with the proverbial grandmother's pace. By learning to drive all over again a woman in Phoenix estimates she has boosted her pickup's fuel economy to 21 miles per gallon from 15, a jump of 40% that surpasses the mileage advertised by its manufacturer, Toyota. With that shift in behavior, she has done more to curb oil consumption than most people zooming around in the latest hybrid cars.

Even without futuristic technologies, drivers can achieve amazing fuel economy in their current cars with nothing fancier than their brains and some lighter feet. The idea is to maintain momentum much as on a leisurely bicycle ride: accelerating only gradually, coasting whenever possible and constantly adjusting speed to minimize the need to stop.

The challenge will be to get Americans to ease up instead of variously slamming on the gas and the brakes. In the meantime, as early eco-drivers lower their own emissions, they are certain to raise tempers of the impatient drivers around them.

Trials in Europe, Japan and the US are finding that drivers commonly improve their fuel economy upwards of 20% after deploying a handful of eco-driving techniques, such as driving more slowly on highways, shifting gears earlier in cities and shutting off the engine rather than idling at long stops.

Technology still matters. A car that is lighter and loaded with the latest environmental hardware will use less gasoline than a car that is heavier and conventional under the hood.

Attempts to promote eco-driving have puttered along for at least a decade, mostly in northern Europe. In 1999, Germany began requiring that elements of eco-driving be taught in driver-education classes, in the land of the autobahn and the Porsche. About 800,000 new drivers get their licenses annually in Germany, and they are supposed to learn three basic eco-driving tips.

First, watch the tachometer, not just the speedometer, and shift gears before the car's engine speed reaches 2,000 revolutions per minute to minimize how hard the engine has to work. Second, don't tailgate, because tailgating requires a lot of unnecessary braking and accelerating. Third, coast if an upcoming light is red, letting it turn green so there is no need to stop.

In the US, where 5% of the world's population consumes 23% of its oil, eco-driving has existed so far mostly as a tiny subculture. In "hypermiling," a quirky new competitive pastime, the winning drivers have surpassed 150 miles per gallon in mass-produced hybrids.

The basic hypermiling technique is the "pulse-and-glide." The driver slowly accelerates to about 60% of full throttle -- the point where a car's engine tends to operate most efficiently -- and then steps off the gas, coasting until the car's speed drops. At the right moment, before losing too much speed, the driver gently presses the gas pedal again.

One tip: Drive as if there is a hot cup of coffee in the cup holder at risk of splashing.

Auto makers are enthusiastic eco-driving promoters. Pressured to improve the fuel economy of their vehicles, they see eco-driving as a way to shift some of the responsibility away from themselves and onto their customers.

Ford has been promoting eco-driving for several years in Germany. Last July, Ford flew German Road Safety Council instructors to Detroit to give an eco-driving lesson to drivers from Pro Formance, the Phoenix professional-driving company. A month later, Ford and Pro Formance staged an eco-driving test with 48 drivers, who improved their fuel economy an average of 24%.

To help drivers make the change, car makers have begun providing technological aids, including dashboard gauges that display fuel economy in real time. If drivers see how their behavior affects their energy consumption, they will be more likely to change.

Within the next two years, Nissan plans to start offering in the US and Japan a feature that it calls the "eco-pedal" -- a sensor that, when the driver is accelerating too piggishly, pushes back against the driver's foot.

But Nissan realizes that slow and steady also is the rule when it comes to changing drivers' behavior behind the wheel. "Not every driver likes to be an eco-driver," notes Nissan's Kazuhiro Doi. So Nissan will include a switch that allows drivers to turn the eco-pedal off. (info fro mThe Wall Street Journal)