We recommend that oil is changed in line with your vehicle's service schedule but for vehicles that only do a low annual mileage then we recommend that the oil is changed at least once per year. The amount of oil needed for a Land Rover Defender varies depending on the specific model and engine type. The table below gives general guidelines regarding the amount of oil required but it is important to always check the owner's manual to confirm the exact oil capacity required for your specific Defender model and engine type.