The automotive industry represents one of the biggest branches of industry. Currently, the competition is big and it is important that all components used are as technologically complete and affordable as they can be. One of the components used in an automobile is a pump. We distinguish water pumps and pumps for oil and fuel. In the final section, we will indirectly take a look at the water pump efficiency, whose purpose is adding smaller amounts of distilled water to a petrol engine. Several tests were made as a part of a project in order to better understand the functioning of the pump itself and its losses.