Six ways to stretch a tank of gas

Buying a hybrid automobile isn't the only way to conserve fuel, reduce emissions and save money at the gas pump. Squeezing just a few more miles per gallon out of your car with some simple adjustments and different driving habits can increase mileage per gallon by as much as 33 percent, according to the Environmental Protection Agency.

The financial benefits of better gas mileage can be significant. Say your car gets 20 mpg and gas costs you $3 a gallon. "If you increase your fuel efficiency by 33 percent, that's a savings of about $44 a month," says Diane MacEachern, author of "Beat High Gas Prices Now!" and founder and CEO of BigGreenPurse.com, which helps women shop for environment-friendly products.

Here are six ways to stretch a tank of gas:

1. Drive smoothly
Eliminating jackrabbit starts, speeding and hard breaking can increase your fuel economy by 33 percent on the highway and 5 percent in the city, netting you up to 92 cents per gallon, the EPA says.

"I don't know many people who would take money out to the driveway and set it on fire," MacEachern says. "You just don't burn up money. But when you put it in the gas tank and drive like mad, it has exactly the same effect."

Editors from the automotive Web site Edmunds.com tested some common driving tips for improving gas mileage and found that driving moderately rather than aggressively has the greatest impact per gallon -- as much as 37 percent improvement in fuel efficiency.

"You see a lot of people doing a lot of mid-range accelerating; the idea is that I need to jump into that little hole in traffic there," says Philip Reed, Edmunds.com's senior consumer-advice editor. "So they're going 55 mph, and they mash the gas pedal and then they're going 70. That type of behavior is extremely fuel-consuming."

Take a long view of the road, Reed advises, and brake slowly when you need to stop.

2. Use cruise control when you can
It's an easy way to keep erratic driving in check.

"When you're on cruise control, not only is the car operating differently and more efficiently, but you're in somewhat of a different frame of mind," Reed says.

His tests found that using cruise control can yield as much as 14 percent better gas mileage.

3. Slow down
Vehicles' optimal cruising speeds vary, so it's worth experimenting with a few tanks of gas to find your car's most efficient speed. That said, higher speeds generally increase aerodynamic drag and decrease gas mileage. The EPA estimates that for every five miles per hour you drive over 60 mph, you pay another 20 cents per gallon of gas.

4. Minimize idling
Reed was surprised at the difference it makes in fuel economy to simply turn off the engine when you stop for longer than a minute. Cutting down excessive idling can save 19 percent of fuel, he says. Cars with bigger engines burn more fuel when idling than cars with smaller engines, according to the EPA.

5. Drop excess weight
Aerodynamics and weight both greatly affect fuel economy, so reconsider your roof racks, cargo boxes and whatever you keep in the trunk. Every additional 100 pounds of weight reduces fuel efficiency by 2 percent. If that weight is on the roof, it adds aerodynamic drag.

When Consumer Reports tested the effect of adding a car-top carrier to a 2005 Toyota Camry, the Camry's mileage per gallon dropped from 35 to 29.

6. Maintain your car
Would you go out of your way to save 55 cents per gallon on gas? The EPA estimates that a well-tuned engine can save its driver 13 cents a gallon. A clean air filter can yield a savings of 32 cents a gallon. And keeping car tires properly inflated can earn you another 10 cents per gallon.

"If everyone's tires were properly inflated, we would be saving about 4 million gallons of gasoline every day," says MacEachern.

LifeWire provides original and syndicated lifestyle content to Web publishers. Joan Shim is a freelance writer and former editor for automotive business magazines.