Aircraft systems and instrumentsQuestion 625 of 934

Which is one of the functions of the engine oil system?

  1. Increasing the fuel octane rating
  2. Measuring the intake air pressure
  3. Removing heat from the cylinders
  4. Generating electrical power for the avionics
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Correct answer: Removing heat from the cylinders

The oil also lubricates moving parts, seals the cylinder walls and pistons, and carries away contaminants.

Source: Pilot's Handbook of Aeronautical Knowledge (FAA-H-8083-25C), Chapter 7: Aircraft Systems — Oil Systems, page 176

Practice aircraft systems and instruments

Questions last reviewed: 18 October 2026