How to Determine Which Gasoline Grade to Use for a Car?

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Methods to check the gasoline grade for a car: 1. Refer to the car's user manual, which records the recommended gasoline grade for the car. 2. The fuel cap usually indicates the fuel grade, recommending which gasoline grade to use and which is optimal. Below is relevant information about gasoline: 1. Currently, in China, the national (IV) gasoline grades include three types: 90, 93, and 97. The national (V) grades are 89, 92, and 95 (with 98 available in the appendix). Gasoline grades are classified by octane rating. 2. If a high-compression engine uses a low-grade gasoline, it can cause a sharp rise in cylinder temperature, incomplete combustion of gasoline, severe engine vibration, resulting in reduced power output, damaged components, increased fuel consumption, and poor driving performance. 3. If a low-compression engine uses a high-grade gasoline, it may lead to "delayed ignition," meaning the auto-ignition point is not reached even at maximum compression, resulting in incomplete combustion, which is also not beneficial for the engine.