Mild hybrid versions of the Ford EcoBoost engine still have a wet belt that drives the oil pump, but this runs under considerably less tension than the timing belt in earlier versions of the engine, so it is not considered as an item that needs replacement. However, it is still crucial to ensure service intervals are maintained and the correct grade of oil is used to ensure its longevity. Changing the oil pump belt would require the timing chain to be removed in order to access it, so we would suggest inspecting the oil pump belt when serviced and budgeting to replace both the chain and belt when required.