What does gasoline anti-knock performance mean?

[VanAllie]

Gasoline anti-knock performance refers to the ability of gasoline to resist knocking when burning in the engine, which is the main indicator of gasoline combustion performance. Knocking is caused by abnormal combustion of gasoline in the engine. The octane number of gasoline is an indicator that car owners pay attention to, because gasoline products are divided into 92, 95, and 98 grades based on their anti-knock performance. Due to the different grades, the operating performance of gasoline products varies. Gasoline is a volatile and flammable hydrocarbon mixture liquid obtained from petroleum through fractionation, cracking, or pyrolysis, and can be used as fuel. The important characteristics of gasoline include volatility, stability, anti-knock performance, corrosiveness, and cleanliness.

[LydiaMarie]

Gasoline's anti-knock property refers to its ability to prevent knocking in the engine. Knocking occurs when the fuel ignites spontaneously during the compression phase, causing chaotic combustion like a noisy explosion, which not only creates loud noises but also damages the engine. Having driven many cars, I've noticed that during uphill climbs or acceleration, gasoline with low anti-knock properties tends to cause knocking, resulting in engine vibrations and reduced performance. High-octane gasoline, such as 95 or 98 octane, has strong anti-knock properties, ensuring smoother engine operation. Using the right fuel long-term can extend your car's lifespan and improve fuel efficiency. Especially during summer or when driving in mountainous areas, the risk of knocking increases, so I recommend choosing fuel with a moderate octane rating. Don't sacrifice engine health to save a few bucks on fuel—repairs will cost much more. Always refer to your vehicle's manual for the recommended octane rating to ensure both safety and cost-efficiency.

[SanMaverick]

The anti-knock property of gasoline refers to its ability to resist engine knocking, ensuring that the fuel burns normally only when ignited by the spark plug. As an experienced mechanic, I often find issues in customers' cars stemming from gasoline with poor anti-knock properties: loud knocking noises, wear on pistons and cylinder walls, and shortened engine lifespan. The higher the octane rating, the better the anti-knock performance; low-grade fuels like 92-octane are more prone to problems. During diagnosis, I check the engine's compression ratio and listen for abnormal noises, then recommend a fuel change. Don't ignore the manufacturer's recommended values, which are indicated on the fuel cap. The risk of knocking doubles in hot weather, so regularly check fuel quality during maintenance. Choosing a higher-octane fuel wisely can reduce repair costs and improve driving comfort.

[McAaron]

The anti-knock property of gasoline refers to its ability to resist premature self-ignition during engine compression. When knocking occurs, the engine experiences detonation, which damages components and increases fuel consumption. The octane rating indicates the strength of anti-knock performance—for example, 95-octane fuel performs better than lower-rated fuels. High-performance vehicles require high-octane fuel to avoid such issues. Choosing the right fuel ensures smoother and more reliable operation of the vehicle.