Does mixing 98 and 95 octane gasoline have any impact?
2 Answers
92 octane gasoline and 95 octane gasoline should not be mixed because they have different isooctane contents. 92 octane gasoline is suitable for engines with low compression ratios, while 95 octane gasoline is suitable for engines with high compression ratios. If 92 octane gasoline is added to a car that requires 95 octane gasoline, abnormal combustion may occur, leading to engine knocking. Knocking not only damages the combustion chamber but also directly affects the normal operation of the engine, and in severe cases, it may cause engine damage. If 95 octane gasoline is added to a car that requires 92 octane gasoline, although it won't damage the engine, 95 octane gasoline is more expensive than 92 octane, resulting in unnecessary costs. Differences between 92, 95, and 98 octane gasoline: Standard gasoline is composed of isooctane and n-heptane. Isooctane has good anti-knock properties, with an octane rating of 100; n-heptane has poor anti-knock properties and is prone to knocking in gasoline engines, with an octane rating of 0. If gasoline is labeled as 92 octane, it means that this gasoline has the same anti-knock properties as standard gasoline containing 92% isooctane and 8% n-heptane. The same principle applies to 95 and 98 octane gasoline. What to do if the wrong gasoline is added: If gasoline with a higher octane rating than required is added (e.g., adding 95 octane when 92 octane is specified), simply switch back to 92 octane gasoline after the current fuel is consumed. If gasoline with a lower octane rating than required is added (e.g., adding 92 octane when 95 octane is specified), you can add a high anti-knock fuel additive. Alternatively, you can drain the fuel tank and refill it with 95 octane gasoline. To find out which gasoline your car requires, refer to the vehicle's user manual or check the fuel grade marked on the fuel filler cap.
As someone who has been driving for many years, I've encountered quite a few situations where 98 and 95 octane gasoline were mixed. It mainly depends on what type of car you have. Modern cars are equipped with adaptive computers that automatically adjust ignition timing to prevent engine knocking. For example, mixing half a tank of 98 and half a tank of 95 octane would result in an octane rating of around 96, which is fine for most regular cars. However, if your car manual specifies the use of 98 octane, mixing might reduce performance, resulting in weaker acceleration or slightly higher fuel consumption. I've driven several car models, and occasionally mixing once to save some money is okay, but don't make it a habit, especially for turbocharged cars. The key is to check the fuel quality at the gas station, as mixing increases the risk of impurities in the fuel pump or injectors. Overall, it's safe, but before long-term use, check your engine requirements to avoid any issues.
