Why is new engine oil as thin as water?

[EdwardRose]

If the oil is drained while the engine is hot, the oil will appear thinner because the distance between lubricant molecules increases at high temperatures, causing the viscosity to decrease. However, the accurate method to determine viscosity is through laboratory equipment measurement, as visual observation is not precise. Here is relevant information about engine oil: 1. Introduction: Engine oil, also known as engine lubricant (English name: Engine-oil), has a density of approximately 0.91×10³ (kg/m³). It serves functions such as lubrication and wear reduction, auxiliary cooling, sealing and leak prevention, rust and corrosion protection, as well as shock absorption. It is often referred to as the 'blood' of a car. 2. Composition: Engine oil consists of base oil and additives. The base oil is the main component of lubricating oil, determining its fundamental properties, while additives compensate for and improve any shortcomings in the base oil's performance, imparting new characteristics. Additives are an essential part of lubricating oil.