🔍 Key Concepts

• Fuel dilution in diesel engine lube oil and how it affects oil properties • How viscosity changes when fuel mixes with lubricating oil • Typical lab/test instruments used in an engine room to monitor lube oil quality

💭 Think About

• Which property of the lube oil changes most noticeably when fuel mixes with it – thickness (flow resistance), acidity/alkalinity, or tendency to form deposits? • Look at each instrument name: which one sounds like it directly compares how easily a fluid flows versus a standard? • Which choices are more related to combustion or chemical properties rather than simple flow behavior?

✅ Before You Answer

• Identify which option refers to flow resistance / thickness of the oil. • Eliminate any option that mainly measures ignition/combustion characteristics rather than oil condition. • Eliminate any option that is primarily for acid/base (neutrality) or deposit formation, not for fuel dilution.