A used car tends to have more worn-out components compared to its original state, which can lead to increased fuel consumption.
Low tire pressure
This is one of the top reasons causing a car to consume more fuel, often due to the habit of driving with under-inflated tires. Operating a vehicle with under-inflated tires causes accelerated wear on the tire’s edges, resulting in increased rolling resistance and higher fuel consumption. If the tire pressure is below the standard by approximately 3PSI, the vehicle can consume about 1-2% more fuel.
Maintaining stable tire pressure around 2.2 – 2.5kg and regularly checking the tires is a way to optimize fuel efficiency, enhance tire longevity, and reduce costs. Alternatively, you can actively monitor tire pressure with a tire pressure sensor system. The alert system will detect and warn you if at least one tire is either under-inflated or over-inflated.
Unbalanced wheel alignment and periodic wheel alignment
Failure to balance a vehicle’s dynamics and periodically align its wheels will lead to increased fuel consumption. Signs include steering wheel vibration, body shaking, unstable steering, uneven tire wear, and extended driving distances, all contributing to higher fuel usage.
To save fuel, have your vehicle dynamically balanced every 6 months or every 8,000 – 10,000 km. Additionally, perform dynamic balancing when changing tires, rotating tires, repairing a punctured tire, or when experiencing steering wheel vibrations. After dynamic balancing, ensure the wheel alignment conforms to the standard angles to prevent uneven tire wear, unstable steering, and jerky driving, which can consume more fuel.
Coolant depletion
While driving, regularly check the engine coolant temperature sensor. If the temperature reading is between 85-90 degrees Celsius, the sensor is functioning properly. Otherwise, if the reading deviates from the upper threshold, it’s likely the sensor is faulty and needs prompt inspection and repair.
When the coolant is depleted, components will exceed the permitted temperature, resulting in several adverse effects, including increased fuel consumption. Ensure the coolant level in the reservoir is between the “Full” and “Low” marks when the engine is cold.
Experts recommend changing the engine coolant after the first 160,000 km, then every 40,000 km per change.
Exhaust system blockage
Any obstruction in the exhaust system increases exhaust gas pressure, subsequently raising fuel consumption. For example, a bent or folded exhaust pipe due to collision. Check the pressure difference between the intake and exhaust in idle mode. If this differential pressure decreases, the catalytic converter may be blocked.
Infrequent engine oil changes
Leaving the engine oil unchanged for an extended period will significantly increase fuel consumption. Failing to replace the oil for a long time renders its lubricating ability ineffective, resulting in increased friction during engine operation, causing increased heat generation and higher fuel consumption.
Apart from these reasons, abnormal fuel consumption might also be due to a dirty engine air filter, long periods without cleaning the fuel injectors, stuck brakes, using the wrong lubricant, or a faulty engine thermostat.
Therefore, when you notice increased fuel consumption, it’s essential to take your vehicle to reputable car care centers for a thorough and accurate examination to identify the root cause.
