An engine oil supply system for a motor vehicle and a method of controlling an engine oil supply system of a motor vehicle is disclosed in which, particularly during an engine overrun period or an engine shut-down, kinetic energy from the slowing engine is used to drive an oil pump so as to store oil in an oil accumulator for later use by one or more engine components without the engine using fuel. The stored oil allows a downsized oil pump to be used thereby saving fuel by providing a supply of oil in addition to or as an alternative to the oil supplied from the oil pump.