What Causes Idle Vibration After Using 95 Octane Gasoline?

[Wood]

This issue arises from combustion problems in the fuel system and should be addressed at an authorized 4S dealership. Below are the differences between 92, 95, and 98 octane gasoline at gas stations: 1. Different Octane Ratings: 92 octane gasoline contains 92% isooctane and 8% n-heptane. 95 octane gasoline contains 95% isooctane and 5% n-heptane. 98 octane gasoline contains 98% isooctane and 2% n-heptane. 2. Different Vehicle Compatibility: 92 octane is suitable for vehicles with lower compression ratios; 95 octane is suitable for high-compression-ratio vehicles; 98 octane is suitable for premium luxury cars and high-performance sports cars. Tips for selecting the appropriate gasoline grade are as follows: 92 octane gasoline is suitable for ordinary cars with lower technical specifications; 95 octane gasoline is suitable for the vast majority of vehicles; 98 octane gasoline is suitable for premium luxury cars and high-performance sports cars.

[Micah]

I've handled many similar cases where engine idling shakes after using 95-octane gasoline, with multiple possible causes. The most fundamental reason is fuel grade mismatch - when a low-compression engine uses high-octane 95 gasoline, the slower combustion can cause misfires and vibrations. Secondly, ignition system issues like worn spark plugs or failing coils may prevent proper fuel ignition. Sensor malfunctions, such as oxygen sensor deviations disrupting air-fuel ratio control, could also be the culprit. Severe carbon buildup might clog fuel injectors, worsening incomplete combustion. My advice: don't delay - immediately connect an OBD scanner to check trouble codes. For simple DIY solutions, try cleaning spark plugs first, or switch back to the appropriate fuel grade like 92-octane to observe changes. Prolonged use of incorrect fuel may damage the engine.