Should a Direct Injection Turbocharged Engine Use 92 or 95 Octane Gasoline?

[MacAnthony]

Direct injection engines are more suitable for using 95 octane gasoline. The differences between 92 and 95 octane gasoline are as follows: Different compositions: 92 octane gasoline consists of 92% isooctane and 8% n-heptane, while 95 octane gasoline is composed of 95% isooctane and 5% n-heptane. Price difference: 95 octane gasoline is slightly more expensive than a tank of 92 octane gasoline. Subtract the price of 92 octane gasoline from that of 95 octane gasoline and multiply by 8 to get the price difference per 100 kilometers of car fuel consumption. Performance variation: 95 octane gasoline, with its higher octane rating, is suitable for engines with higher compression ratios. As the engine speed increases, the ignition timing in the cylinder advances. When the speed reaches a critical point, the air-fuel mixture in the cylinder may ignite prematurely before the spark plug fires, a phenomenon known as knocking. Increasing the gasoline's octane rating can effectively enhance its anti-knock properties.