With gas prices escalating again to expected highs of $4.00 per gallon or more, it’s wise to take another look at our driving habits.

The Department of Energy’s consumer website offers motorists advice about keeping your car in shape, planning trips, choosing a vehicle and the following, about driving more efficiently:

Drive Sensibly

Aggressive driving (speeding, rapid acceleration and braking) wastes gas. It can lower your gas mileage by 33 percent at highway speeds and by 5 percent around town. Sensible driving is also safer for you and others, so you may save more than gas money.

Fuel Economy Benefit: 5–33%
Equivalent Gasoline Savings: $0.17–$1.15/gallon

Observe the Speed Limit

While each vehicle reaches its optimal fuel economy at a different speed (or range of speeds), gas mileage usually decreases rapidly at speeds above 60 mph.

You can assume that each 5 mph you drive over 60 mph is like paying an additional $0.28 per gallon for gas.

Observing the speed limit is also safer.

Fuel Economy Benefit: 7–23%
Equivalent Gasoline Savings: $0.24–$0.80/gallon

Remove Excess Weight

Avoid keeping unnecessary items in your vehicle, especially heavy ones. An extra 100 pounds in your vehicle could reduce your MPG by up to 2 percent. The reduction is based on the percentage of extra weight relative to the vehicle’s weight and affects smaller vehicles more than larger ones.

Fuel Economy Benefit: 1–2%/100 lbs
Equivalent Gasoline Savings: $0.03–$0.07/gallon

Avoid Excessive Idling

Idling can use a quarter to a half gallon of fuel per hour, depending on engine size and air conditioner (AC) use. Turn off your engine when your vehicle is parked. It only takes a few seconds worth of fuel to restart your vehicle. Turning your engine on and off excessively, however, may increase starter wear.

Fuel Cost Savings: $0.01–$0.03/min. (AC off)
$0.02–$0.03/min. (AC on)

Use Cruise Control

Using cruise control on the highway helps you maintain a constant speed and, in most cases, will save gas.

Use Overdrive Gears

When you use overdrive gearing, your car’s engine speed goes down. This saves gas and reduces engine wear.

Note: Cost savings are based on an assumed fuel price of $3.48/gallon.

Data Sources

Estimates for fuel savings from sensible driving are based on Energy and Environmental Analysis, Inc., Owner Related Fuel Economy Improvements, Arlington, Virginia, 2001.

Estimates for the effect of speed on MPG are based on a study by West, B.H., R.N. McGill, J.W. Hodgson, S.S. Sluder, and D.E. Smith, Development and Verification of Light-Duty Modal Emissions and Fuel Consumption Values for Traffic Models, Oak Ridge National Laboratory, Oak Ridge, Tennessee, March 1999.