Is it okay to mix half 92 and half 98?
3 Answers
Vehicles that require 98-octane gasoline should not mix in 92-octane fuel, as this can lead to insufficient anti-knock properties, increased engine failure rates during operation, and issues such as higher fuel consumption, increased carbon deposits, and clogged fuel injectors. Reason Analysis: Generally, the fuel type recommended on the vehicle's fuel tank cap should be followed, or a higher octane fuel can be used. However, using a lower octane fuel is not advisable. Vehicles that use 92-octane fuel can switch to 98-octane, but vehicles that require 98-octane should not use 92-octane. The primary difference between gasoline of different octane ratings lies in their anti-knock performance, which is a crucial indicator of fuel quality. 92-octane gasoline has an octane rating of 92 and is suitable for mid-range vehicles (with lower compression ratios). 95-octane gasoline consists of 95% isooctane and 5% n-heptane and should be used in engines with higher compression ratios. 98-octane gasoline has an octane rating equivalent to a mixture of 98% isooctane and 2% n-heptane. The advantages of 98-octane gasoline are 'two highs and two lows': higher anti-knock performance and power output, along with lower harmful substances and exhaust pollution. Fueling Precautions: Vehicles should not arbitrarily switch to a lower octane fuel. Doing so may cause premature combustion of the gasoline, leading to engine knocking. Incomplete combustion can also result in increased carbon deposits, which may clog conduits and injectors, as well as reduce vehicle power and increase fuel consumption.
I've also faced this dilemma before. Mixing 92 and 98 octane gasoline in the short term isn't a big issue since they're both gasoline. It's like cooking rice with different brands mixed together - at most, the texture might be slightly different. However, the extra money spent on 98 octane would be wasted because its anti-knock advantage gets diluted by the 92 octane. Moreover, the ECU in modern cars will automatically adjust ignition timing to adapt to the mixed octane rating, which might make the driving experience feel less stable in terms of power delivery. As an experienced driver, my advice is to either stick with 92 octane to save money or go straight for 95 octane. This half-hearted mixing approach really isn't worthwhile, and over time it might even increase engine carbon deposits.
It depends on the car model. I've tried mixing fuel grades when driving a turbocharged car. The engine didn't malfunction, but I clearly felt some sluggishness during acceleration. 98-octane fuel has higher octane rating suitable for high-performance cars - mixing it with 92-octane is essentially downgrading premium fuel, which is quite wasteful. Also, gas station attendants mentioned different gasoline grades have varying additive formulations, and mixing might compromise cleaning effectiveness. If it's just for emergency use occasionally, no big deal. But for long-term use, maintaining a mixed fuel tank isn't beneficial for your car. It's better to simply fill up with the manual-specified grade for peace of mind.
