6 Reasons Your Car Has Bad Gas Mileage

How many miles does your car get to the gallon? Depending on your make and model car -- and whether you drive on the highway or city roads -- you can expect to get about 20 to 26 miles per gallon (MPG). If you find yourself filling up at the pump more frequently, it could be a sign of one of the following problems.

#1) Dirty Air Filter

A dirty air filter can restrict airflow to the engine and subsequently cause bad MPG. Refer to your owner's manual for more information on when and how to replace the air filter. In some cases, you may simply be able to clean the air filter instead of replacing it.

#2) Worn Spark Plugs

Of course, worn spark plugs is another common cause of bad MPG. Over time, it's not uncommon for spark plugs to lose their ability to create spark. When this occurs, fuel is left unburned in your engine's combustion chamber; thus, resulting in wasted fuel and subsequent bad MPG. Consider having your spark plugs replaced if you experience bad MPG, rough idling or trouble starting your car with a cold engine.

#3) Underinflated Tires

Another common cause of bad gas mileage is underinflated tires. When tires lack the necessary air pressure, it forces the vehicle to work extra hard. This extra work leads to increased fuel consumption and reduced performance.

#4) Driving with a Heavy Foot

Your driving habits also play a role in your car's MPG. If you drive with a heavy foot -- always hitting the gas and accelerating -- you'll inevitably burn more gas. It's just that simple.

#5) Clogged Fuel Injectors

Clogged or otherwise faulty fuel injectors can cause bad MPG. As the name suggests, fuel injectors are designed to inject fuel into the cylinders. When they become clogged, they aren't able to efficiently transfer fuel from your tank to the cylinders, resulting in a loss of MPG. You can use a fuel additive product to clean your car's fuel injector. Or, if you really want to make sure they are clean, consider having them replaced.

#6) Air Conditioning

No, that's not just a myth. Using the air conditioner can lower your car's gas mileage. With that said, opening the windows isn't a better alternative. When the windows are open, your car becomes less aerodynamic, causing it to burn more fuel.