Before you decide to ease your pain at the pump by downsizing your vehicle or even by switching to public transportation, why not change your driving habits and boost your miles per gallon by 20 percent to 40 percent?

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That's right -- 20 percent to 40 percent! Others have done it and you can, too -- but we're not talking here about slowing from 85 mph to 75 mph on the highway. We're talking serious changes -- the changes made by "hypermilers" -- drivers who have perfected the art of harnessing the power of every single drop of gas -- to slash that $75 a week gas tab down to less than $50.

How do you do it? Installing an inexpensive miles-per-gallon display, increasing tire pressure and driving slower would make for a good start. Sure, you don't like the sound of it -- but wouldn't it be music to your ears if that $4 gallon of gas felt like $2.69?

Saving gas by driving better
Wayne Gerdes runs the Web site Cleanmpg.com and is credited with coining the term "hypermiling." He defines hypermiling as simply beating the Environmental Protection Agency, or EPA, combined mileage estimates on a vehicle from the time you drive it off the lot until the time you trade it in. Gerdes says he started trying to get more efficiency from his vehicles when the twin towers went down Sept. 11. He saw oil as not just a commodity but one that funneled funds back to regions that harbored anti-American sentiment. His practice of hypermiling grew, and in 2005, at the Prius Marathon, he drove a stock Toyota Prius 1,397 miles on a single tank of fuel -- 110 miles per gallon. Gerdes, who averages 45 miles per gallon in his 2005 Honda Accord in everyday driving, says interest in hypermiling has spiked along with gas prices.

Fast facts

• 1 less pound of tire pressure can lower fuel efficiency by 1.4 percent. • Shifting at 1,000 rpm less than usual can mean 5.5 percent better fuel efficiency. • Most cars operate most efficiently at 40 mph to 55 mph. • If your engine is going to idle for more than seven seconds, it's better to turn it off.

"There are any number of reasons for hypermiling: global security, global warming, local smog, currency translations or trade deficits. Or, it could just be that you want more money in your pocket instead of giving it to the gas station," says Gerdes. He recommends that drivers start by bringing tire pressure up to the maximum recommended on the sidewall, changing oil to a lightweight synthetic and installing a ScanGauge or similar fuel-consumption display for real-time feedback. The device displays real-time miles-per-gallon numbers and can instantly show drivers how their habits affect fuel consumption.

"People just don't know when they step on the throttle or accelerator how bad it is. When they see it in real time, they can make slight adjustments to that. What we're seeing is that just with that (and the increased tire pressure and proper setup), a 15 (percent) to 20 percent immediate increase in economy barely doing anything," says Gerdes.

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