🔍 Key Concepts

• Effect of fuel dilution on lubricating oil properties (viscosity, film strength, flash point) • What centrifuging, filtering, and straining actually remove from oil (type of contaminants) • Manufacturer/engineering practice when oil is chemically or physically altered, not just dirty

💭 Think About

• Ask yourself: does fuel dilution mean there are solid particles in the oil, or has the oil itself been thinned/contaminated by another liquid? • Which treatment methods (centrifuging, filtering, straining) are designed mainly for removing water or solids, and which action is taken when the oil’s basic lubricating properties are no longer reliable? • Consider engine safety: if oil is excessively thinned by fuel, what is the safest maintenance action to protect bearings and moving parts?

✅ Before You Answer

• Identify whether fuel in lube oil is a solid, water, or another liquid hydrocarbon and how that affects oil quality • Match each option with the type of contamination it best addresses: solids vs water vs chemical/physical breakdown of the oil • Think about standard engineering practice: when oil is excessively contaminated so that its properties are changed, what is the recommended corrective action?