Generally, there are no scheduled oil changes for jet engines. During engine maintenance, however, oil filters and seals are checked and changed if necessary. There are monitors on the flight deck for oil quantity, pressure and temperature, unlike in a car where an oil light is the only indicator. While my car takes about four litres of oil, the Airbus A320 requires four times that amount and consumes about half a litre per flight hour. Typical “top–ups” are done on a daily basis, so jet engines always have some fresh oil but rarely need a complete oil change.