Can Audi A4 Use 92 Octane Gasoline?

[MacPresley]

Audi A4 cannot use 92 octane gasoline; it requires 95 octane gasoline. The difference between 92 and 95 octane gasoline: 92 octane gasoline consists of 92% isooctane and 8% n-heptane, while 95 octane is composed of 95% isooctane and 5% n-heptane. The slightly higher cost of 95 octane gasoline is due to its greater proportion of isooctane. The importance of choosing the right gasoline: If a high-compression engine uses low-octane gasoline, it can lead to incomplete combustion, severe engine vibration, reduced power output, engine component damage, increased fuel consumption, and lack of driving power. Conversely, if a low-compression engine uses high-octane gasoline, it may result in delayed combustion—where the fuel does not reach its auto-ignition point even at maximum compression—leading to incomplete combustion. This necessitates additional fuel injection to maintain power output, which not only offers no benefit to the engine but also increases fuel consumption.