5 ways to boost your summer road trip MPG
With gas prices down, you may be joining the millions of Americans taking a summer road trip. But even with gas $1 a gallon lower than last summer, you want to get the best possible gas mileage so you can spend that money on fun instead of at the pump.
You probably know that how you drive can affect your gas mileage significantly, but what about how you pack? Just ask the scientists at Oak Ridge National Laboratories, who operate the fueleconomy.gov website for the Environmental Protection Agency and U.S. Department of Transportation. They've developed tips for boosting your mileage.
Here are the details on improving your road trip MPG from fueleconomy.gov and other expert sources:
Keep luggage off the roof. Tempting though it is to stuff the family's gear in a rooftop cargo box, try to avoid it. That box increases wind resistance and at Interstate speeds of 65 to 75 MPH, it can cut gas mileage by up to 25 percent. Even in slower highway driving, the MPG loss is up to 17 percent. That's equivalent to paying 47 cents more per gallon of gas. If you just can't avoid external cargo storage, get a box that mounts on the rear bumper, which has lower wind drag and a fuel penalty of only 5 percent in highway driving.
Don't tailgate. You already know that shadowing the bumper of the car in front of you is dangerous, but it also dents gas mileage. The Oak Ridge scientists estimate that aggressive driving -- braking followed by rapid acceleration -- can cut MPG by up one-third in highway driving. That's the equivalent of adding up to 90 cents a gallon to your fuel costs.
Use cruise control. This aid to driving at a steady speed on expressways helps you avoid the temptation to speed up and change lanes frequently only to have to slow down again. In setting your speed, you probably want to go with the traffic flow. But fueleconomy.gov points out that above 50 miles per hour, each additional 5 miles per hour faster is equivalent to paying 19 cents more per gallon of gas.
Use your air conditioner wisely. Obviously, you don't want your family to suffer in the heat. But how you use your air conditioner can help cut the burden it puts on gas mileage. If the car has been parked, open the windows and let out the hot air before you turn on the air conditioner. Start the air conditioning after you're already driving. Especially avoid idling with the air conditioner running.
Check your tires. Underinflated tires are unsafe, and they cut gas mileage. Tires inflated one-fourth below the recommended pressure can cut MPG 3 percent to 5 percent. The recommended tire pressure for your vehicle is on a plaque that's visible when the driver's door is open.
Even before you leave on your trip, the fueleconomy.gov website can help you budget for your gas expenses. My Trip Calculator helps you map your route and then gives cost figures for the car you own. If you have more than one vehicle and are trying to choose which to take on the road, the calculator will compare the gas costs of up to three models.
