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Knowing what oil viscosity you need for your car is important to ensure your engine starts and runs smoothly but what does it actually mean?

Oil viscosity essentially means the thickness of the oil- whether it is closer to runny honey or thick treacle- and the rate at which it flows.

You may have seen the acronym ‘SAE’ when looking for oil and wondered what it might mean. Well, SAE stands for Society of Automotive Engineers and this is used as an industry standard for oil viscosity based on the rate of flow at a given temperature.

You will also have seen two numbers separated by a ‘W’. As an example, 5W-30. The first number refers to how well the engine oil flows when the engine is cold- like engine startup. The second number refers to how well the engine oil flows when the engine is at normal operating temperatures. The lower the number, the thinner the oil and easier it will flow. The higher the number, the thicker the oil and more protection it can give at higher temperatures. The ‘W’ stands for ‘Winter’- referring to the starting the engine in colder temperatures in Winter.

For example, a 5W-30 oil viscosity is thinner and will be more suited to colder temperatures than a 10W-30. A 10W-40 oil viscosity will be more suited to higher temperatures than a 10W-30.

Your OEM will tell you the oil that your car needs in the vehicle handbook to ensure the engine runs with the optimal oil viscosity to protect the engine and also provide the highest efficiency.

Keep your engine healthy with high-quality Motul engine oils, innovated and formulated to give you the optimal efficiency and protection for your engine.