Is Using 95 Octane Gasoline Beneficial for Emissions During Annual Inspection?

[SanDamian]

During the annual inspection, if an engine designed for 92 octane gasoline is filled with 95 octane, the result will be incomplete fuel combustion, leading to unburned fuel being expelled as exhaust. In this scenario, the vehicle's emissions test will show excessive levels of hydrocarbons and particulate matter. Therefore, using 95 octane gasoline during the annual inspection is not beneficial for emissions. The differences between 92 and 95 octane gasoline are as follows: Different Anti-Knock Properties: The octane rating represents the fuel's anti-knock properties. A higher octane number indicates better anti-knock performance. Different Isooctane Content: 92 octane gasoline consists of 92% isooctane and 8% n-heptane, while 95 octane gasoline consists of 95% isooctane and 5% n-heptane. Different Prices: A tank of 95 octane gasoline is slightly more expensive than a tank of 92 octane gasoline.