Travel light. You don't operate as well when you you're wearing a 20-pound backpack. Your car doesn't like lugging excessive weight either. An extra 100 pounds in your vehicle can reduce miles-per-gallon by 2%. That translates to between 4 and 7 cents a gallon. If you must lug stuff, use the trunk, not a roof rack, which creates a lot of aerodynamic drag.
Stop idling: Sitting still with the engine chugging burns up to half a gallon an hour, so kill the engine when you're parked. You'll save 1 to 3 cents a minute versus idling with the air conditioning off, and 2 to 4 cents a minute if you had the air conditioning on.
Take care of the basics: A simple tuneup can save 16 cents a gallon, and don't forget to change your oil. You want your engine humming, not bumming, for maximum efficiency.
Use cruise control: Savings vary, but it's usually a smart move on an open highway.
Know where you're going: With all the GPS gizmos and websites like MapQuest.com out there, were you really going to rely on instinct to get to an unfamiliar destination? Yeah, guys, we're talking to you. Going 25 miles out of your way -- and another 25 miles back -- will cost many of you about $10 in gas.
Get a gas-saver: It's probably too late for this weekend, but have you considered buying a more fuel-friendly car? Based on today's prices, if you drive 15,000 miles in a year, a 30 mile-per-gallon auto will cost you around $900 less at the pump than a 20-mile-per-hour vehicle.