Why mpg drop

Excessive idling decreases MPG. Driving at higher speeds increases aerodynamic drag wind resistance , reducing fuel economy. The new EPA tests account for aerodynamic drag up to highway speeds of 80 mph, but some drivers exceed this speed.

Cold weather and frequent short trips can reduce fuel economy, since your engine doesn't operate efficiently until it is warmed up. In colder weather, it takes longer for your engine to warm, and on short trips, your vehicle operates a smaller percentage of time at the desired temperature.

Note: Letting your car idle to warm-up doesn't help your fuel economy. It actually uses more fuel and creates more pollution. Cargo or cargo racks on top of your vehicle e.

MPG tests do not account for this type of cargo. Towing a trailer or carrying excessive weight decreases fuel economy. Vehicles are assumed to carry only three hundred pounds of passengers and cargo during testing. Running electrical accessories e. Driving on hilly or mountainous terrain or on unpaved roads can reduce fuel economy.

The EPA test assumes vehicles operate on flat ground. Using 4-wheel drive reduces fuel economy. Should there be a leak then less fuel gets to the engine causing poor gas mileage.

Air conditioning is necessary when it's really hot. Just remember, that it also decreases gas mileage. When possible, open your windows. Use car oils that are high in friction reduction. Choose either a synthetic or what your owner's manual recommends. In the winter, you don't really need to let your car idle to warm it up. All it really needs is 30 seconds. Still, because it's cold, you may want to warm up the vehicle for you! Getting into a warm vehicle is always preferable to getting into a cold one.

However, when you're waiting for someone, either turn off your car or put it in neutral. This will save gas and help the environment! When you need help getting your car or truck to run efficiently, turn to the service pros at Joe Bowman Auto Plaza! Luckily, the fix is easy. Stop at your closest gas station with an air machine and fill your tires up. Not sure how? Some tire shops even have a complimentary service. Dirty or worn out spark plugs affect the way your engine burns fuel in the combustion chamber.

Worn out spark plugs causes gas to be left unburned, wasting it. Air filters are somewhat delicate, made of pleated paper or thin fabrics. Like underinflated tires, this is an easy fix. Most air filter changes can be made at home as they are easily accessible and replaceable. Usually, oxygen sensors last the life of the car.

Which is good, because they are responsible for the air-to-fuel ratio of your engine. Typically, faulty O2 sensors send false, lean-bias alarms.