What Causes the Fuel Consumption Display to Fluctuate Erratically?
2 Answers
During fuel sloshing in the tank, poor contact of the fuel level sensor (fuel float) can also affect the variation in average fuel consumption values. In such cases, it's important to observe whether the fuel gauge needle also fluctuates up and down. Insufficient energy in the ignition system, particularly from spark plugs causing ignition fluctuations, can lead to incomplete fuel combustion, resulting in erratic fuel consumption readings. Factors affecting fuel consumption include: 1. Rough Roads Consume More Fuel: Driving on congested or uneven roads for extended periods in lower gears inevitably increases fuel consumption; 2. Overloading the Trunk Increases Fuel Usage: Using the trunk as a storage space, cramming it with unnecessary items, increases the vehicle's weight. It's important to note that vehicle weight and fuel consumption are directly proportional. A 10% reduction in vehicle weight can lead to a corresponding percentage decrease in fuel consumption; 3. Incorrect Driving Habits Can Double or Triple Fuel Usage: Poor driving habits have the most significant impact on fuel consumption. During driving, especially in heavy traffic, at red lights, or when changing lanes, sudden acceleration and hard braking are the most common issues.
The erratic fuel consumption display was something I encountered when driving my old car, mostly due to faulty sensors. The fuel flow sensor is prone to dirt buildup or oil contamination, causing unstable signals and fluctuating readings. It could also be caused by aging wiring with poor contact, especially during rainy days when moisture can lead to short circuits. Instantaneous fuel consumption naturally rises during acceleration, but erratic display is abnormal and could indicate a data error in the vehicle's computer or voltage fluctuations. I recommend using a diagnostic tool for inspection as soon as possible. I once tried cleaning the sensor myself, but it had little effect—professional servicing is more reliable. Ignoring this issue may lead to false engine warnings, affecting overall safety. Spending a little money for peace of mind is worth it.
