Which condition increases knock risk in internal combustion engines using high-octane fuel?

💡 Explanation

When intake air temperature is elevated, auto-ignition risk increases because adiabatic compression raises the end-gas temperature close to the fuel's auto-ignition point, initiating rapid, uncontrolled combustion (knock). Therefore, elevated intake temperature increases knock risk, rather than decreased compression, increased EGR, or retarded ignition, which reduce it.

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