Tasks performed by engine oil
Task 1: Lubricates
Forms a permanent lubricant film between the moving surfaces in the engine. Cylinders and pistons, in particular, must be adequately lubricated in order to prevent piston seizure. Lubrication provides protection against wear, thereby extending the engine's life, and reducing friction also saves fuel.
Task 2: Cleans
Keeps the engine clean. Special additives protect hot, moving engine parts from any contamination that may arise during the combustion process (or from use of biofuels such as biodiesel). The additives absorb impurities in the oil, preventing harmful deposits in the engine.
Task 3: Neutralizes
Neutralizes acids formed by combustion gases and unburnt fuel in the oil, thereby preventing corrosion – especially in the bearings.
Task 4: Cools
Dissipates heat. Oil cools many parts of the engine not reached by the coolant.
Types of engine oil
There are basically three different classes of engine oil, each with different properties. Mineral oils are the most widely-used base oils. They can be manufactured relatively easily and cheaply by distilling and refining crude oil. Semi-synthetic engine oils are considerably better quality, especially regarding their aging resistance and thermal properties. Their production is a complex process.
Synthetic oils are manufactured by chemical synthesis and can be given very specific quality-enhancing properties. Their optimum performance makes these oils particularly suitable for high-performance engines such as the engine in your
Multi-grade oils are the engine oils commonly used today. They are based on low-viscosity base oils and mixed with special additives (e.g. polymers such as polyester and polyisobutylene), so that their viscosity is only slightly reduced at higher temperatures.
With temperature having little effect on their viscosity, multi-grade oils are better suited than single-grade oils to covering a wider temperature range. They can maintain an optimal supply of oil to the engine in both hot and cold conditions. This results in greater lubrication when starting the engine from cold, reduced strain on the starter motor at low temperatures, and adequate lubrication at higher ambient and engine temperatures.
The numbers above the oil application range define its SAE (Society of Automotive Engineers) class. For multi-grade oils, this covers two grades e.g. 0W-40. These specify the operating temperature range for which the oil is best suited. The number before the “W” (Winter) indicates how viscous the oil is at low temperatures: the lower the number, the better the oil's fluidity. “0W” therefore denotes extremely low-viscosity oil, for use at low temperatures.
The second part of the viscosity grade (the number after the “W”) indicates how viscous the oil is at high temperatures: the higher the number, the thicker the oil film. 10 would therefore represent very low-viscosity oil which is specifically designed for cold regions. In extremely hot areas, even an oil classed as “60” can be used, as it is highly viscous in its normal state. In the 0W-40 example, “40” signifies average viscosity, which guarantees optimum performance even at high temperatures.
Porsche Classic Motoroil
The elixir of life for your classic car.
Mobil 1 - The engine oil for your
Throughout our motorsport history, we've tested a great many engine oils on the race track. That’s how we know Mobil 1 is the optimum oil for