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:
$0.19–$1.28/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 $0.31 per gallon for gas.
Observing the speed limit is also safer.
Fuel Economy Benefit:
7–23%
Equivalent Gasoline Savings:
$0.27–$0.89/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:
$0.04–$0.08/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–$0.04/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 $3.87/gallon.
Keep Your Engine Properly Tuned
Fixing
a car that is noticeably out of tune or has failed an emissions test
can improve its gas mileage by an average of 4 percent, though results
vary based on the kind of repair and how well it is done.
Fixing a serious maintenance problem, such as a faulty oxygen sensor, can improve your mileage by as much as 40 percent.
Fuel Economy Benefit:
4%
Equivalent Gasoline Savings:
$0.15/gallon
Keep Tires Properly Inflated
You
can improve your gas mileage by up to 3.3 percent by keeping your tires
inflated to the proper pressure. Under-inflated tires can lower gas
mileage by 0.3 percent for every 1 psi drop in pressure of all four
tires. Properly inflated tires are safer and last longer.
The proper tire pressure for your
vehicle is usually found on a sticker in the driver's side door jamb or
the glove box and in your owner's manual. Do not use the maximum
pressure printed on the tire's sidewall.
Fuel Economy Benefit:
Up to 3%
Equivalent Gasoline Savings:
Up to $0.12/gallon
Use the Recommended Grade of Motor Oil
You can improve your gas mileage by 1–2
percent by using the manufacturer's recommended grade of motor oil. For
example, using 10W-30 motor oil in an engine designed to use 5W-30 can
lower your gas mileage by 1–2 percent. Using 5W-30 in an engine designed
for 5W-20 can lower your gas mileage by 1–1.5 percent. Also, look for
motor oil that says "Energy Conserving" on the API performance symbol to
be sure it contains friction-reducing additives.
Fuel Economy Benefit:
1–2%
Equivalent Gasoline Savings:
$0.04–$0.08/gallon
NEW INFORMATION: Replacing a Clogged Air Filter on Modern Cars Improves Performance but Not MPG
A new study
shows that replacing a clogged air filter on cars with fuel-injected,
computer-controlled gasoline engines does not improve fuel economy but
it can improve acceleration time by around 6 to 11 percent. This kind of
engine is prevalent on most gasoline cars manufactured from the early
1980s onward.
Tests suggest that replacing a clogged
air filter on an older car with a carbureted engine may improve fuel
economy 2 to 6 percent under normal replacement conditions or up to 14
percent if the filter is so clogged that it significantly affects
drivability.
The effect of a clogged air filter on diesel vehicles will be tested in the near future.
Note: Cost savings are based on an assumed fuel price of $3.87/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.
Fixing
a car that is noticeably out of tune or has failed an emissions test
can improve its gas mileage by an average of 4 percent, though results
vary based on the kind of repair and how well it is done.
You
can improve your gas mileage by up to 3.3 percent by keeping your tires
inflated to the proper pressure. Under-inflated tires can lower gas
mileage by 0.3 percent for every 1 psi drop in pressure of all four
tires. Properly inflated tires are safer and last longer.
shows that replacing a clogged air filter on cars with fuel-injected,
computer-controlled gasoline engines does not improve fuel economy but
it can improve acceleration time by around 6 to 11 percent. This kind of
engine is prevalent on most gasoline cars manufactured from the early
1980s onward.