The U.S. Environmental Protection Agency estimates that a 2001 Honda Civic can get 33 miles per gallon on highways, but John Anderson has achieved 45 mpg through driving techniques known as "hypermiling."

He's slowed his freeway speed down to 65 mph and uses cruise control whenever possible. At a stop, he gently shifts his five-speed car. And when going downhill, he puts his car in neutral.

"It's funny because 65 is the speed limit," said Anderson, who lives and works in Alpine. "But I get the dirtiest looks from people who whiz by, like I'm going 40 on the freeway."

Hypermiling is part art of understanding one's inefficient driving habits and part science of understanding how a car burns gasoline. The aim is to beat government fuel-mileage estimates.

Some hypermilers claim to have achieved well over 100 mpg in hybrid vehicles through techniques like cutting the engine and cruising for blocks, rolling through stop signs, tailgating semitrailers to avoid wind resistance, over-inflating tires to reduce the amount of tire surface touching the road and using motor oil that provides the least resistance on the engine. Some drivers refrain from using air conditioning in the summer. One driver was even reported to have made a habit of getting out of the car and physically rolling it to avoid wasting gas to back up.

Some hypermiling practices are criticized as unsafe. For instance, when drivers increase their speeds by 10-15 mph to enable them to coast for several blocks at slower speeds, "what happens is you've become this erratic person on the road," AAA Utah spokeswoman Rolayne Fairclough said.

And some of the techniques are counter-intuitive to the idea of saving money on gas, which on Tuesday averaged a record high of $4.09 for a gallon of regular unleaded in Utah.

"Turning your car off and on so much, really, it is wear and tear on your battery and starting motor," Fairclough said. "You could, in the long run, cause more damage and costlier damage."

Anderson said that for him, hypermiling isn't about money, but the principle of paying so much for gas. "I thought, what can I do to save, to cut?"

He thinks that some of the techniques used by die-hard hypermilers are extreme. He prefers comfort over higher gas mileage and still uses air conditioning.

Anderson began hypermiling as he researched a story about the techniques for the monthly magazine he edits, Healthy Utah. The article will be in August's edition.

"My goal was to see if I could get over 40," he said. "Normally, with a 12-gallon tank, I get 340 miles to a tank."