Motor oil is a type of lubricant used in internal combustion engines. Its primary function is to reduce friction between moving parts and protect them from wear and tear. Motor oil also helps to cool the engine and keep it clean. The type of motor oil that is best for a particular vehicle depends on a number of factors, including the make and model of the car, the age of the engine, and the climate in which the car is driven.
For a 2013 Audi A4, the recommended motor oil is a synthetic 5W-30 oil. This type of oil is designed to provide excellent protection against wear and tear, even in extreme driving conditions. It is also able to withstand high temperatures without breaking down. In addition, synthetic 5W-30 oil is less likely to cause sludge and deposits to form in the engine.