🔍 Key Concepts

• How temperature affects the viscosity (thickness) of fuel oil and lube (lubricating) oil • What component(s) make an engine "turn over" more slowly: batteries/starter vs internal friction • The role of lubricating oil in engine friction and cranking speed

💭 Think About

• Think about which fluid directly affects how hard it is for the crankshaft to turn when the starter begins cranking the engine. • Ask yourself: in extreme cold, which of these options would become much thicker, making it harder for the engine to rotate at normal starting speed? • Consider whether excessive starting air pressure or low lube oil viscosity would slow cranking, or if they would cause a different type of starting problem instead.

✅ Before You Answer

• Compare how cold temperature affects viscosity of fuel oil vs lube oil: which one most affects cranking speed rather than combustion quality? • Decide which option would increase internal friction in bearings and moving parts during cranking. • Eliminate any choice that would more likely cause combustion issues (poor burning) instead of a slow-turning engine.