Does 0.5 cm above the oil level limit have any impact?
3 Answers
Being 0.5 cm above the oil level limit has no impact. The normal range for engine oil is between the two marks on the dipstick. Engine oil, also known as motor lubricant, consists of base oil and additives. It serves multiple functions such as lubrication, reducing friction, aiding in cooling, sealing against leaks, preventing rust and corrosion, and acting as a shock absorber. It is often referred to as the 'lifeblood' of a car. Engine oil is composed of base oil and additives. Base oils are categorized by quality into Group I, Group II, and Group III base oils, with Group I and II being mineral oils and Group III being synthetic base oils. There are various types of additives, and the quantity and quality of these additives directly influence the API quality rating of the lubricant.
Having the engine oil 0.5 cm above the upper limit does have negative effects. An excess of 0.5 cm means there's too much oil, which can increase crankcase pressure, cause foaming during engine operation, and reduce lubrication efficiency. I've encountered such cases when repairing cars—excess oil can lead to oil seal leaks or damage sealing rings, and over time may cause abnormal noises or increased fuel consumption. In severe cases, it can even affect the emission system, resulting in blue smoke from the exhaust pipe. When checking, it's best to measure the oil dipstick again with the engine off and cooled down to ensure the level is between the upper and lower limits. If you find it's overfilled, avoid long-distance driving immediately; instead, find a clean environment and use a small oil extractor to remove the excess. During routine maintenance, be careful not to overfill, and always double-check the oil level after each oil change.
Adding 0.5 cm extra engine oil may have negative effects. Exceeding the oil level slightly above the upper limit might seem insignificant, but I've encountered many friends who experienced malfunctions after such operational errors, such as unstable oil pressure causing engine vibrations or increased noise. Excessive oil splashing during operation can increase crankshaft rotation resistance, indirectly raising fuel consumption. Checking is simple: pull out the dipstick half an hour after parking, wipe it clean, reinsert it, and read the level. If it's indeed too high, don't panic—visit a repair shop for professional oil extraction or DIY with simple tools. For prevention, always check the manual for the required amount before adding oil, and avoid pouring extra based on intuition. Long-term neglect may accelerate component wear and affect vehicle stability.
