What should you circle in red when an oil change is performed?

• A. Oil level
• B. Engine operating time
• C. The date of the change
• D. The amount of oil added

Answer: (B)

When an oil change is performed, it is essential to circle the engine operating time in red on the AFTO Form 781. This practice serves to clearly indicate the amount of time the engine has been operated since the last oil change, allowing for easy reference for future maintenance and ensuring that oil changes are performed within specified intervals. Keeping track of engine operating time helps in scheduling necessary maintenance activities and assessing the overall condition of the engine.

Other aspects such as the oil level, the date of the change, and the amount of oil added are important for maintenance records but circling the engine operating time specifically highlights when the oil change service was conducted relative to the engine usage, which is vital for ongoing maintenance planning.