Pack Your Trunk, Not the Roof

Want to improve your gas mileage by 5 percent instantly? Lose the roof rack when you're not using it.

Although a roof rack or carrier provides additional cargo space that may allow you to buy a smaller car, the extra wind drag from a loaded roof rack can decrease your fuel efficiency by 5 percent, according to U.S. Department of Energy. If space is truly at a premium, and you need to use a roof rack to secure skis, snowboards, and other bulky equipment, remove the roof rack as soon as you're done hitting the slopes to minimize the mileage drop.

Difficulty level: Easy