Volatility is a measure of how easily an oil evaporates at high temperatures. The higher the volatility, the more easily the oil evaporates. This can cause problems because it can lead to deposits forming on engine parts, which can eventually cause engine damage. Engine oils with low volatility are therefore generally considered to be better for engines. Volatility can be measured in a number of ways, but the most common method is to measure the oil’s boiling point. The higher the boiling point, the lower the volatility.
There are a number of factors that can affect an oil’s volatility, including the type of oil used, the way it’s made, and the conditions under which it’s used. For example, synthetic oils typically have lower volatility than petroleum-based oils. And oils that are designed for high-performance engines usually have higher volatility than those designed for more mundane applications.
Engine oils can also be classified according to their viscosity, which is a measure of how thick they are. The thicker an oil, the slower it flows and the higher its viscosity. High-viscosity oils are generally better for high-performance applications because they can provide better protection against wear and tear. However, they can also cause problems because they can make it difficult for an engine to start in cold weather.
Finally, engine oils can also be classified according to their additives. Additives are chemicals that are added to the oil to improve its performance in some way. Common additives include anti-wear agents, detergents, and dispersants. Each additive serves a specific purpose, and the right combination of additives can help an engine run more smoothly and efficiently.
When it comes to choosing the right engine oil for your car, it’s important to consider all of these factors. The type of oil you use, the way it’s made, and the conditions under which it will be used can all affect its performance. And, of course, you’ll also want to make sure that you choose an oil that’s appropriate for your car’s engine. With so many different types of engine oils on the market, it can be tough to know where to start. But if you keep these factors in mind, you should be able to find an oil that’s right for your car.
Volatility is the property of the lightest fractions of the engine oil to evaporate at high temperatures, which is expressed as a percentage of loss from evaporation after heating the engine oil for one hour at 250 °C.
To determine the vaporizability, or volatility, of motor oil, the Knock method is used. If 850 grams of engine oil are left after heating 1,000 grams of engine oil at 250 °C for one hour, this means that the volatility is 15% (minus 150 grams).
According to ACEA requirements, A1/B1 class oils must not volatilize more than 15%, A3/B3, A3/B4, A5/B5, C1, C2, C3, E4, E6, E7, E9 must not exceed 13%, and C4 oils must not volatilize more than 11% or equal to 11%. If the engine oil is too volatile, it will have to be filled more often and therefore the oil consumption will be high.
To learn more about volatility, watch this video on car engine oil.