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

[GavinLee]

It is normal for the engine oil to be exactly at the upper limit. Engine oil is a lubricant for the engine, and its functions are: 1. to cushion the impact load on the piston, piston pin, connecting rod, and crankshaft bearings; 2. to form a sealing ring between the piston ring and the piston, reducing gas leakage and preventing external pollutants from entering. The effects of overfilling engine oil on the car are: 1. causing the crankcase to explode; 2. the engine exhaust pipe emitting blue smoke; 3. piston ring sticking and fuel injector clogging; 4. reducing the engine's output power; 5. engine oil leakage. The parts lubricated by engine oil include: 1. the valve train; 2. crankshaft bearings; 3. the piston; 4. the engine crankshaft chamber; 5. the gasoline engine piston; 6. the hydraulic lifter and hydraulic tappet.