What Type of Cars is 98 Octane Gasoline Suitable For?

[ZoeyFitz]

98 octane gasoline is suitable for cars with an engine compression ratio above 10. It is composed of 98% isooctane and 2% n-heptane. The gasoline octane rating represents the ratio of the actual gasoline's anti-knock performance to that of standard gasoline, with higher ratings indicating stronger anti-knock properties. The octane number of gasoline is a unit that measures its anti-knock performance under lean mixture conditions, numerically equal to the volume percentage of isooctane in the standard fuel that matches the anti-knock performance of the sample under specified conditions. The standard fuel consists of a mixture of isooctane and n-heptane: 1. Isooctane is used as a standard for excellent anti-knock performance, with an octane number set at 100; 2. N-heptane is used as a standard for poor anti-knock performance, with an octane number of 0, representing the tendency to cause knocking in gasoline engines.

[ElijahLynn]

After using cars for so many years, I've learned that 98-octane gasoline is mainly for high-performance vehicles, such as sports cars like Porsche and Lamborghini. Engines with high compression ratios require high-octane gasoline to prevent knocking. For ordinary family cars like the Corolla, manufacturers usually recommend 92 or 95-octane fuel—there's no need to spend extra on 98-octane. Last time, my friend drove a Mercedes-AMG to refuel, and the maintenance manual clearly stated that 98-octane was mandatory; otherwise, the engine would produce a knocking sound. Turbocharged German cars also often recommend 98-octane fuel. If the vehicle manual doesn’t require 98-octane, using it would just be a waste of money—saving on fuel costs could even let you drive dozens of kilometers more. Remember, occasionally switching to higher-octane gasoline during long trips or aggressive driving can slightly improve power response.

[VanEleanor]

At the repair shop, we often encounter car owners asking about 98-octane gasoline. To be honest, most cars don't need it. This type of fuel is suitable for luxury cars with engine compression ratios exceeding 10:1, such as performance vehicles like BMW M series or Audi RS models. For regular SUVs or domestic family cars, the engines are designed to run on 92/95-octane fuel. Using 98-octane not only costs more but also doesn't provide any advantages. Some owners mistakenly believe that higher-octane fuel can clean carbon deposits, but the effect is minimal. On the other hand, we've seen Porsche 911 owners fill up with 92-octane fuel, and the engine warning light immediately came on. My advice is to check the owner's manual in the glove box before refueling—just use the octane rating recommended by the manufacturer. Using the wrong fuel grade long-term can affect the lifespan of oxygen sensors, and the repair costs could cover two years' worth of fuel expenses.

[DiMaci]

I think 98-octane gasoline has only two purposes: satisfying supercar owners and rich car enthusiasts' psychological needs. When driving my friend's GTR, he insisted on using 98-octane, claiming it allows higher engine RPM without knocking sounds. But my Civic has been running on 92-octane for five years, and the engine remains perfectly smooth. Only high-compression ratio engines truly need 98-octane fuel - using it in regular commuter cars is just burning money. The price difference at the pump makes it obvious: spending nearly 100 yuan extra per tank is worse than buying a milk tea. Though cars with modified ECUs might require higher-octane fuel, stock factory vehicles really don't need to follow this trend.