🔍 Key Concepts

• Pour point definition for lubricating oils • How low temperature performance of oil relates to solid components within the oil • The role of impurities vs. natural constituents of the base oil

💭 Think About

• Which factor in the choices would most directly change the temperature at which the oil stops flowing? • Among centrifuging, wax, water, and acid: which one is known to crystallize or solidify and interfere with flow at low temperatures? • Think about what refiners try hardest to remove or control when producing low-pour-point lubricating oils.

✅ Before You Answer

• Be clear on what pour point means: the lowest temperature at which oil will still flow • Identify which option is a natural, temperature-sensitive component of many mineral oils • Separate in your mind what affects corrosion or cleanliness from what affects flow at low temperature.