What Causes Poor Engine Performance and High Fuel Consumption?

[EdwardDella]

The reasons for poor engine performance and high fuel consumption are as follows: 1. Fuel system faults: A clogged or waterlogged air filter reduces air intake, leading to an overly rich air-fuel mixture, incomplete combustion, and sluggish acceleration. In this case, black smoke will be visibly emitted from the exhaust pipe. Cracks in fuel lines or loose/leaking connections, as well as insufficient fuel pump pressure, can cause poor fuel delivery, resulting in weak acceleration. 2. Electrical faults: A faulty mass airflow sensor reduces intake air volume, causing an excessively rich or lean mixture and affecting acceleration performance. Individual cylinder spark plug failure (i.e., misfiring) also impacts acceleration. Overheating or a faulty coolant temperature sensor similarly affects acceleration. A clogged catalytic converter or faulty oxygen sensor can also cause poor engine acceleration. 3. Mechanical faults: Wear and tear on engine valves, cylinder liners, pistons, or rings can lead to insufficient cylinder compression. Excessive intake valve clearance, insufficient exhaust valve clearance, or valve leakage can cause misfiring and affect acceleration. Worn timing belts (or chains) that cause incorrect ignition timing (either too early or too late) will also impact acceleration performance.

[Virgil]

After driving for so many years, the lack of power and high fuel consumption in my car is really frustrating. My car used to have the same issue, and I later found out it was caused by excessive carbon deposits leading to incomplete combustion in the engine, which weakened the power and increased fuel consumption. It could also be due to a dirty air filter blocking the intake or aging spark plugs failing to ignite properly, affecting overall performance. I remember replacing the spark plugs with new ones and immediately feeling the car regain power, with fuel consumption dropping significantly. Additionally, using low-quality gasoline can cause similar problems, so it's important to choose reliable gas stations. Regular maintenance is crucial—checking the fuel filter and injectors every few thousand kilometers can prevent minor issues from becoming major ones. Driving habits also play a key role; frequent rapid acceleration and hard braking only increase fuel consumption. Driving steadily is both fuel-efficient and safer. If you notice any issues, it's best to get them checked by a professional as soon as possible.

[StKinsley]

The car lacks power and has high fuel consumption. I've researched this issue multiple times, and it may stem from carbon deposits inside the engine, especially on the fuel injectors and intake valves, which clog the mixture of fuel and air, leading to decreased combustion efficiency, insufficient power, and soaring fuel consumption. Other common causes include a dirty air filter restricting air intake, incorrect spark plug gaps causing untimely ignition, or a faulty oxygen sensor leading to an imbalanced air-fuel mixture. I recommend regularly cleaning carbon deposits, using high-quality fuel additives for prevention, and replacing the air filter and spark plugs every few years—simple steps that can save money. Aged engine oil can also increase friction resistance and affect fuel consumption, so timely oil changes are crucial. Additionally, avoid sudden acceleration while driving and maintain a steady speed to significantly reduce fuel consumption.

[DelAxel]

As a seasoned driver, I've seen many cases of cars lacking power and having high fuel consumption, mainly caused by irregular maintenance. Changing engine oil and oil filters must be done promptly; otherwise, increased wear on engine components raises friction resistance, naturally leading to higher fuel consumption. A dirty air filter restricts airflow, reducing power and potentially damaging the engine. Spark plugs should be replaced every few tens of thousands of kilometers as they age. If these measures don't help, the issue might be a clogged fuel system or faulty sensors. My experience suggests addressing problems early to avoid worsening fuel waste and vehicle damage. Drive smoothly by accelerating gently and braking softly, avoid overloading the car to reduce burden, and regularly check tire pressure—low pressure increases rolling resistance and fuel consumption.