Is it okay for the engine oil to be exactly at the upper limit?

[MacBradley]

It is acceptable for the engine oil to be exactly at the upper limit, as it will not cause any issues, but it must not exceed this marking line. Excess oil can easily overflow into the combustion chamber (due to excessive internal pressure), leading to a buildup of carbon deposits over time, and in severe cases, it may even cause oil burning. Therefore, when adding engine oil, car owners must always pay attention to the position of the marking line. If the oil level indeed exceeds the upper limit, it should be promptly addressed at a nearby auto repair shop, where staff will use specialized equipment (an oil extractor) to remove the excess oil. Engine oil, also known as engine lubricant, serves to lubricate and reduce friction, assist in cooling, seal against leaks, prevent rust and corrosion, and provide shock absorption for the engine.