What does 92 gasoline mean?

[Wayne]

92 gasoline refers to fuel with an octane rating of 92 and a heptane content of 8, suitable for mid-range vehicles (with relatively low compression ratios). On December 18, 2013, the General Administration of Quality Supervision, Inspection and Quarantine and the Standardization Administration of China jointly issued the fifth-phase national standard for automotive gasoline. Currently, gasoline is classified into four grades: 89 (formerly 90), 92 (formerly 93), 95 (formerly 97), and 98 (a newly introduced grade). These numbers represent the octane rating of the gasoline, indicating its anti-knock properties, and are unrelated to the cleanliness of the fuel. High-compression engines require higher-grade fuel. The higher the fuel grade, the lower the combustion knock, and the higher the required engine compression ratio. Conversely, lower-grade fuel produces more combustion knock and is suitable for engines with lower compression ratios. The fuel grade also relates to engine ignition timing. Lower-grade gasoline burns faster, requiring a retarded ignition angle, while higher-grade fuel burns slower, requiring an advanced ignition angle.