Why do 4S shops add engine oil to the highest point?

[JasmineLynn]

4S shops add engine oil to the highest point because the car is in a hot state when owners go to 4S shops for maintenance. There are two points to note when adding engine oil: 1. When selecting engine oil: it is necessary to strictly follow the engine oil grade specified in the car manual. If there is no engine oil of the same grade, you can use a higher grade, but you cannot use a lower grade instead; 2. When adding engine oil: the amount of engine oil added should be slightly lower than the standard scale. Too much engine oil will increase the rotation resistance of the crankshaft, reduce the output power of the engine, and excessive engine oil will enter the combustion chamber to participate in combustion, causing the vehicle to burn engine oil, emit blue smoke, and even increase fuel consumption.