Final answer:
Adding engine oil to a CMV is part of routine servicing, which is essential for maintaining the vehicle in a good condition and preventing breakdowns.
Step-by-step explanation:
Adding engine oil to your Commercial Motor Vehicle (CMV) is considered as part of routine servicing. Routine servicing includes regular maintenance tasks that are performed on a schedule to keep the vehicle in good working condition. These tasks are designed to prevent breakdowns and extend the life of the vehicle. Adding engine oil, along with checking tire pressure, replacing air filters, and other similar maintenance activities, is essential for the smooth operation of the CMV.