- Thermal Expansion: When your engine is hot, the metal components have expanded due to the elevated temperatures. Adding cold motor oil to a hot engine can cause sudden and extreme temperature changes, which can stress and potentially damage engine parts.
- Rapid Evaporation: Hot oil can rapidly evaporate when coming into contact with hot engine surfaces, potentially leaving critical engine parts under-lubricated and vulnerable to wear and tear.
- Oil Thinning: High temperatures can cause motor oil to become thinner and less viscous. Adding cold oil to hot oil can further reduce its viscosity, reducing its effectiveness as a lubricant.
- Spills and Burns: Handling hot oil can increase the risk of spills or burns. Motor oil is flammable, so it's safer to add oil when the engine and oil are at a cooler temperature.
To ensure the safety of your engine, always wait until it has sufficiently cooled down before adding motor oil. Consult your vehicle's owner's manual for the recommended waiting time before checking or adding oil.
