Is 95 Octane Gasoline Mandatory for Turbocharged Engines?

[MacJordan]

Turbocharged engines do not necessarily require 95 octane gasoline. Here are the relevant details: 1. Requirements: German brand turbocharged engines generally recommend using 95 octane gasoline, while other brands do not impose strict requirements. Vehicle owners can check the instructions on the inside of the fuel tank cap for specific details. The gasoline requirement for an engine is determined by its compression ratio. Typically, engines with higher compression ratios require higher-octane gasoline to withstand greater pressure and prevent knocking. Air entering a turbocharged engine undergoes an additional compression stage via the turbocharger, resulting in a larger compression ratio. In theory, higher-octane gasoline is indeed preferable. 2. Gasoline Differences: The main difference between 92 and 95 octane gasoline lies in the varying proportions of heptane and isooctane. 92 octane gasoline contains 92% isooctane and 8% heptane, while 95 octane gasoline contains 95% isooctane and 5% heptane. The differing ratios of heptane and isooctane directly affect the anti-knock properties of the gasoline. The octane rating actually represents the anti-knock performance, with higher numbers indicating better resistance to knocking.