Why has the fuel consumption suddenly increased?

[JamesonRose]

Here are the reasons for increased fuel consumption: 1. Spark plugs: After prolonged use, the tips of spark plugs can accumulate carbon deposits or become worn, leading to inefficient ignition. Severe cases may cause incomplete combustion of gasoline and reduced power output. To compensate for the lack of power, the vehicle's computer will automatically increase fuel injection, which is a significant reason for increased fuel consumption. If this is the cause, timely replacement of spark plugs is necessary. 2. Oxygen sensor: Another reason for increased fuel consumption could be severe contamination of the vehicle's oxygen sensor. In such cases, the oxygen sensor cannot accurately measure the intake air volume. During operation, this leads to insufficient air in the cylinders, resulting in lower fuel efficiency and consequently higher fuel consumption.