The correct engine oil is important for proper performance, so i and a long durability and reliability of the car.
The correct oil namely ensures smooth running of the engine. Oil creates between the mechanical parts of the layer and so prevents the parts to each other directly to spawn and opotřebovávali and protects the engine.
In addition, the oil keeps the vehicle engine VOLVO XC90 4.4i from dirt and oxidation. Just depends on oil. Oil is produced in different viskozitách. Viscosity is a measure of the internal friction. What is the oil heat, this is the internal friction of the higher rate. For comparison-such as honey has a higher viscosity than water. Viscosity directly depends on the ambient and indoor temperatures and must correspond to a specific engine. The viscosity of the oil to find out directly from the designation. Oils are referred to as 5W-30. The first number indicates the viscosity of a cold, which indicates the following letter(W=WINTER).The first number is lower, the oil less viscous. Lower viscosity cold helps the engines better start in cold environments, because it creates less resistance. The second number indicates the viscosity at high temperatures. This, again, must meet the requirements of your engine.