Can Petroleum and Petrochemical Products Be Mixed?
3 Answers
Petroleum and petrochemical products can be mixed without causing chemical reactions. Similarly, gasoline with different octane ratings can also be mixed without chemical reactions, but mixing different octane ratings may result in a decrease in the octane value, which could lead to engine knocking. The gasoline composition from different branded gas stations is generally similar, but it is still recommended to refuel at reputable stations. Many small gas stations sell substandard gasoline, and prolonged use of such low-quality fuel can increase carbon deposits in the engine and reduce the lifespan of the catalytic converter. When refueling, it is important not only to choose reputable large gas stations but also to select the correct gasoline octane rating.
Last time I ran out of gas on the highway and had to pull into a Sinopec service station, even though my tank still had some PetroChina 92-octane fuel left. After mixing them temporarily, I drove over a hundred kilometers without any issues. Actually, all gasoline is produced according to national standards, and base oils of the same grade are essentially identical in quality. However, different brands have varying additive formulations, and long-term mixing might affect carbon deposit cleaning performance. As my auto repair shop mechanic said, occasional emergency mixing is fine, but sticking to the same brand's additives can better protect the engine. With so many gas station promotions now, I plan my routes in advance to avoid mixing. After all, my car has been with me for five years, and I want to take good care of it.
Last week, I helped a customer inspect an old LaCrosse. The owner mentioned that he frequently mixes 95-octane gasoline from the two major oil companies. We tested the fuel lines and spark plugs and found no abnormal deposits. National standards require that the core indicators of gasoline must meet the specifications, and it is indeed feasible to mix gasoline of the same grade from different brands. However, for high-end cars, it's important to note that the Porsche 4 owner's manual explicitly recommends avoiding mixing gasoline from different brands. The principle is simple: although the base oil is the same, differences in detergent formulations can affect the combustion chamber's performance. I suggest that mixing brands temporarily is fine for regular family cars, but for performance vehicles, it's best to stick to a single brand. During each maintenance session, you can use a borescope to check for carbon deposits inside the cylinders.
