Why is 92 octane gasoline recommended for a compression ratio of 13?

[OClara]

This situation mainly occurs in Mazda engines, which have a compression ratio of 13 but can use 92 octane gasoline. This is primarily because the engine has been structurally designed specifically for lower octane gasoline, and engines without such design cannot adopt this approach. More reasons are explained as follows: 1. Reason one: To reduce engine knocking, this engine features a specially designed exhaust manifold. The long exhaust manifold design is used to minimize the impact of exhaust heat on the combustion chamber temperature. 2. Reason two: The engine also reduces the temperature of the piston and combustion chamber by installing an oil spray nozzle under the piston, preventing knocking caused by high temperatures and the relatively poor anti-knock properties of 92 octane gasoline. 3. Reason three: This mainly applies to Mazda engines with special designs. For ordinary engines with a compression ratio of 13, 95 octane gasoline should be used.