Police monitoring hypermilers

Boise_Motorists who try to increase their gas mileage by coasting with their engines off, drafting behind big rigs and driving much slower than the speed limit may be acting dangerously and even illegally, officials say.

"Hypermilers," as they're known, say those techniques and others, such as overinflating tires, can help them get 80 to 100 miles a gallon in a normal car, saving on gasoline that costs more than $4 a gallon.

"The goals of hypermiling are positive, such as eliminating aggressive driving and saving energy," Marshall L. Doney, AAA Automotive vice president, told the Idaho Statesman. "Unfortunately, some motorists have taken their desire to improve fuel economy to extremes with techniques that put themselves, as well as their fellow motorists, in danger."

Adam Winstral of Boise uses some of the techniques but doesn't consider himself a hypermiler.

"Coasting to red lights, turning the engine off at long red lights," he said. "It's simple, and you don't have to piss others off.

"If somebody's on my tail and there's a red light ahead, I might give it a little gas to avoid the rage. However, (if) nobody's behind me, I'm just coasting in."

He conducted his own experiment, first driving as usual without being much concerned about conserving gas and got 30.29 miles per gallon.

The next time he filled up, "I tried to drive extremely conservative, coasting when possible, being aware of my foot on the gas pedal," he said. "This worked out to 35.83 miles per gallon."

He said that adds 52 miles per tank of gas.

Experts say Winstral's techniques won't cause problems but warn that other gas-saving methods - driving way below the speed limit, coasting through stop signs and turning off the engine to coast - can be dangerous.

Driving too slowly, or driving on the white line, can also attract unwanted attention, said Rick Ohnsman, a spokesman for the Idaho State Police.

"Even if we learn they're not drunk, they could get a ticket for failure to maintain a lane," Ohnsman said.

Motorists can also be ticketed for tailgating if they are drafting. Driving too closely behind another vehicle can increase the risk of an accident.

"It might save a little, but not nearly enough to warrant the danger," Ohnsman said. "The savings are minimal, anyway."

Copyright 2008 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.