What are the symptoms of poor fuel quality?
3 Answers
Symptoms of poor fuel quality include: noticeably reduced vehicle power, more severely unstable idling, or even unexpected stalling; increased and rapid fuel consumption; long-term use can lead to carbon deposits and fuel residue, affecting the engine and fuel injectors. Below are related introductions: 1. Octane number: Gasoline grades are determined based on the octane number. The higher the octane number, the better the anti-knock performance. 2. Leaded gasoline: Gasoline containing lead components can cause oxygen sensor poisoning, clog the exhaust pipe and three-way catalytic converter, and reduce engine power. After using leaded gasoline, the spark plug insulator usually appears white or yellow. 3. Gum content: Gum content indicates the stability of gasoline. Excessive gum content can lead to deposits in the intake system or sticking of the intake valve. Generally, the unwashed gum content in gasoline before adding detergent should be below 30mg/100ml.
It feels particularly off when driving. When accelerating, the engine makes a sputtering noise, and the tachometer needle jumps erratically. Sometimes, the car even lurches forward suddenly. Last time I was overtaking on the highway, this exact issue happened, scaring me into easing off the throttle. It's even worse at low speeds—I can feel the car shaking at red lights, and the exhaust emits black smoke with a sour, foul smell. The most annoying part is the inexplicable spike in fuel consumption. Previously, a full tank could last 500 kilometers, but after filling up with some low-quality fuel, it dropped straight to 420.
I've seen quite a few cars break down due to poor fuel quality, with very typical symptoms. Not only does the engine warning light suddenly come on, but cold starts become particularly difficult, requiring several turns of the key before the engine fires up. At idle, the steering wheel vibrates so much it makes your hands numb, and the color of the water dripping from the exhaust pipe looks off. One Passat owner mentioned that the engine yellow light came on the day after refueling, with the diagnostic code showing multiple cylinder misfires. This kind of fuel contains many impurities that can easily clog the fuel injectors and, in severe cases, damage the catalytic converter, with repair costs easily exceeding five or six thousand yuan.
