Does it matter if the engine oil is exactly at the maximum mark?
2 Answers
Having the engine oil exactly at the maximum mark is not an issue and will not cause any damage to the engine. However, if the oil level exceeds the upper limit, it can increase the internal operating resistance of the engine, making it harder for the engine speed to rise quickly when the accelerator is pressed. Additionally, it may damage the three-way catalytic system. When adding engine oil, it's advisable to refer to the maintenance guidelines to determine the exact amount of oil required for the engine. For vehicles that consume oil, it's important for owners to regularly check the oil level. If the oil level approaches the lower limit, it should be topped up promptly. If too much oil is accidentally added, exceeding the upper limit, a specialized tool should be used to remove the excess. If a vehicle is burning oil, the crankcase ventilation system should be inspected, as prolonged oil consumption can lead to damage to the three-way catalytic converter.
Every time I check my car's engine oil and it's right at the maximum mark, I feel a bit uneasy. Although theoretically it's fine because the dipstick range is safe, too much oil can cause foaming inside the engine, affecting lubrication. Especially during high-speed driving, the oil gets agitated, foams up, leading to insufficient friction, faster component wear, and increased fuel consumption. Once, my car had this issue, and after a long trip, the engine sounded rougher. The mechanic said foaming oil reduces cooling efficiency and could damage gaskets. I make it a habit to park on level ground, turn off the engine, wait ten minutes to cool, then measure—wiping the dipstick clean and inserting it twice to get an average reading. The ideal is to keep it at the midpoint to avoid potential hazards from tilted readings. A small tip: don’t skip the waiting time; measuring hot oil isn’t accurate.
