What is the total capacity of the APU oil system?

The total capacity of the APU oil system is correctly identified as six quarts. This specification is important for maintaining the APU's operational efficiency and longevity. Ensuring the proper oil level is crucial because the APU requires a sufficient amount of oil to lubricate its internal components, particularly during start-up and operation. The six-quart capacity provides an adequate reservoir to accommodate the demands of the APU while allowing for effective cooling and minimizing wear on the components. This knowledge is essential for performing routine inspections and servicing of the APU to ensure optimal performance and reliability.