Is It Good to Use Higher-Octane Gasoline?

[LeWillow]

Using higher-octane gasoline does not necessarily bring absolute benefits. The type of fuel to use should be determined based on the vehicle's manual and the instructions on the fuel tank cap. For any vehicle model sold in China, manufacturers must make targeted adjustments according to domestic road conditions and fuel quality. Here are some relevant details: 1. Gasoline Octane Rating: In fact, the gasoline octane rating refers to its octane number, not purity. It is an important indicator of gasoline's anti-knock performance. Generally, when crude oil is initially refined, the octane number is at most 90#. After adding various anti-knock additives, it becomes higher-octane gasoline such as 93, 95, or 97. 2. Characteristics of Higher-Octane Gasoline: Higher-octane gasoline has lower combustion knock but burns more slowly, requiring a higher compression ratio. Conversely, lower-octane fuel burns faster but has higher combustion knock, requiring a lower compression ratio. 3. Factors in Choosing Gasoline Octane: Therefore, the octane rating of gasoline should be selected based on the engine's compression ratio. Typically, naturally aspirated engines with a compression ratio exceeding 10, especially those with direct injection technology, require a higher compression ratio and thus need higher-octane fuels like 95 or 97. Meanwhile, naturally aspirated or turbocharged engines with lower compression ratios require lower-octane fuels like 93. 4. Risks of Blindly Using Higher-Octane Gasoline: Since higher-octane gasoline has less knock, the engine may run quieter. However, because the car's engine control program is designed to optimize parameters like compression ratio and ignition timing for the specified fuel, it includes adaptive adjustments for lower-octane gasoline but lacks corresponding adjustments for higher-octane fuel. As a result, engines with low compression ratios using higher-octane gasoline may experience incomplete combustion, leading to sluggish acceleration and increased carbon deposits.