Can I Switch from 98 Octane to 95 Octane Gasoline?

[Mandy]

Whether you can switch from 98 octane to 95 octane gasoline mainly depends on whether your car's fuel recommendation supports 95 octane. If it does, you can make the switch. Below are the details: Relationship Between Octane Rating and Anti-Knock Performance: Higher octane gasoline offers better anti-knock performance. When the air-fuel mixture is injected into the cylinder, the piston moves upward to compress the mixture. As pressure increases, so does temperature. If the gasoline's anti-knock performance is too low, combustion may start before the spark plug ignites, leading to knocking (commonly known as engine knock). Knocking not only affects engine output but can also cause damage to the engine. Choosing the Right Octane Rating for Your Vehicle: 92 octane gasoline is suitable for ordinary cars with lower technical requirements. 95 octane gasoline is suitable for the majority of vehicles. 98 octane gasoline is ideal for turbocharged engines and vehicles with higher compression ratios, as it is compatible with most cars.

[Janet]

After driving for so many years, I've tried different octane gasoline. Switching from 98 to 95 is fine in the short term since they're both standard gasoline, and the slight difference in octane rating has minimal actual impact. However, long-term switching requires attention: high-compression engines like turbocharged models benefit from 98's better anti-knock properties, and switching to 95 might slightly reduce perceived power. Don't worry about mixing fuels in the tank—the car's ECU automatically adjusts ignition timing to adapt. I tested 95 for a few months, and city driving fuel consumption differed by at most 0.5L/100km. Savings are real but require long-term calculation. Older cars don't matter as much—my neighbor's decade-old Accord has been running on 92 all along. The key is checking your vehicle manual's recommended octane; occasionally using 95 is no big deal.

[StJourney]

A while back, when fuel prices surged sharply, I switched from 98-octane to 95-octane gasoline to save some costs. Real-world testing showed noticeable differences in turbocharged vehicles: throttle response lags slightly during highway driving, and floor acceleration produces louder engine noise. The gas station attendant explained this is due to 95-octane's lower knock resistance, causing the ECU to automatically retard ignition timing. However, the difference is almost imperceptible in naturally aspirated engines – my wife's Polo showed no change after switching. Do check your fuel cap for minimum octane requirements though, as many German luxury cars mandate 95-octane as baseline. Don't worry about mixing fuels – topping up half-tank 98 with new 95 works fine. After calculating, I found monthly savings of about 200 yuan, though maintenance intervals need advancing slightly. Ultimately, it's a personal trade-off.

[KingstonFitz]

After working at a gas station for five years, I often get asked this question. Switching from 98 to 95 depends on the car model: For turbocharged vehicles like BMW and Mercedes, the fuel cap usually indicates 95 or above. Suddenly switching to a lower octane in these cars may cause knocking sounds. However, most naturally aspirated Japanese cars specify 92 or above, so 95 is more than sufficient. Don’t panic if you accidentally fill up with the wrong fuel—modern cars have knock sensors to automatically protect the engine. The real concern is certain modified cars with ECU tuning, which must use higher-octane fuel. For daily commuting, 95 octane is perfectly adequate and saves money. I even have Porsche customers who use 95 long-term. Just remember to clean carbon deposits regularly.