Sterling Parts Blog

6 Reasons for Poor Fuel Economy 2019 Updated

January 21 2019

Posted in car care

Tagged car care


1. Correct Octane Fuel

Your car engine needs a specific fuel type which is listed in your car manual. It is always known by its octane number. Always stick to that type because that is the optimum fuel needed for your engine. Refer to vehicle logbook to determine which fuel to use for your car. Most cars have a label inside the fuel flap indicating which fuel to use.


2. Driving Habits

If you are accelerating too aggressively, it will lead to an increase in fuel consumption. Lot of people would accelerate their vehicles too much and then brake aggressively to go around turns. This not only reduces your mileage but puts a strain on your car parts. For example your car clutch wears out faster, the life of the car suspension reduces and you may have to get your brake pads changed sooner due to harder braking. Your car parts as a whole will take a beating.


Also, if your vehicle has an economy mode or fuel saving mode, use this to assist with improving your fuel economy.


3. Fuel Injectors

As their names imply, the function of fuel injectors is to inject fuel into the car engine. They play a major role in how a car engine performs. If you fuel injector is leaking, that means the car is consuming more fuel than what is required to run. This reduces your car mileage. The symptom of a leaky fuel injector apart from poor mileage is the smell of fuel. The oversupply of fuel can also be if your fuel injector is not closing properly. This happens due to a faulty spring or poor maintenance such as developing of rust.


4. Correct Tire Pressure

A single tire underinflated by 10 psi costs about 3.3% of your fuel economy. Why? If your tire is deflated, more of the tire comes in contact with the ground and due to this, the friction between the tire and the ground increases. Consequently, the engine has to burn more fuel to go the same distance as now it has to overcome this increased friction. Remember to always consult your car manufacturer about the optimum tire pressure in your car. Do not however go by the tire pressure rating given by the tire manufacturer.


5. Oxygen Sensors

An oxygen sensor is located on the inside of a car’s exhaust pipe and is responsible to sense the amount of oxygen present in the mixture. It is a feedback mechanism for the Engine Control Unit (ECU) to adjust the amount of fuel entering in the engine. If the oxygen sensor fails, your fuel mixture will be either too rich (high fuel, low oxygen) or too lean (low fuel, high oxygen). This leads to an inefficient fuel burn and hence reduces the car mileage.


6. Spark Plugs

A spark plug fires the air and fuel mixture inside the engine. The timing of the spark plug firing the engine is critical for the optimal fuel burn. If too soon or too late, the combustion will not be complete in an engine due to which traces of unburnt fuel may also be seen at the exhaust. The reason for this could be damage to the spark plug electrodes or fouled spark plug. A fouled spark plug is one which is covered with dust, oil or carbon. Due to misfiring of the spark plug, the combustion is not proper and hence the mileage of the car also drops. Symptoms of this faulty car part are engine misfires, low mileage, hard starts, lack of acceleration and rough idling.