The normal operation of the engine is inseparable from the lubrication and protection of the engine oil. Therefore, if you want the engine to work well, you must not choose the wrong engine oil. When choosing engine oil, manufacturers usually provide instructions. For example, some models are suitable for 5W40 engine oil. What does this mean?
What does 5w40 stand for?
Internationally, engine oil generally has two labels, namely SAE label and API label. For example, "5w40" is an SAE label. So what does "5w40" stand for?
The "w" in "5w40" represents winter, and "5w" represents the viscosity of engine oil under low temperature conditions.
As we all know, under low temperature conditions, engine oil will thicken and become less fluid, which will affect the lubrication performance of the engine oil. Therefore, under low temperature conditions, it is necessary to choose an engine oil with a thinner viscosity to ensure good fluidity. The number before "w" represents the viscosity of the engine oil at low temperatures.
So how to identify this viscosity index? Generally, you can subtract 35 from the number in front of w, which is the minimum temperature suitable for modified engine oil. For example, 5w means it can be used in conditions as low as -30°C. This "5" represents the freezing point temperature. The smaller the number, the stronger the fluidity under low temperature conditions.
"40" is an indicator of the high temperature resistance of engine oil, representing the kinematic viscosity of the engine oil at 100°C. The higher the number, the higher the viscosity and the stronger the ability to withstand high temperatures.
The thinner the oil, the better, right?
The viscosity of engine oil we see at normal temperature does not represent its viscosity at high temperatures, nor does it represent its viscosity at low temperatures. The viscosity of engine oil changes with temperature. High-quality engine oil should have a viscosity that can still lubricate various components at high temperatures and still have good fluidity at low temperatures.
The viscosity of high-end engine oil is relatively low, but it does not mean that the thinner the oil, the better. Instead, refer to the instructions and choose the most appropriate engine oil according to the manufacturer's regulations on oil viscosity to achieve the best results.
Does engine oil become thinner with use or thicker with use?
Engine oil becomes thinner first and then thickens. Because most engine oils contain viscosity index improvers, when sheared for a long time, the viscosity index improvers will be sheared by the shear force and lose their original viscosity, causing the viscosity of the oil to decrease to a certain extent; a period of time After a while, due to the oxidation of the oil, a large amount of sludge and some impurities are produced, which are dispersed in the oil by the detergent and dispersant, causing the viscosity to increase.
The above introduces the meaning of 5w-40 to everyone. When choosing engine oil, many people do not know how to choose, and sometimes they misbelieve what others say, leading to a series of problems. In fact, generally if you choose according to the manufacturer's regulations on engine oil viscosity, there will be no problems. Even if it is not the best performance, it will be the most suitable.
What does 5w40 stand for?
Internationally, engine oil generally has two labels, namely SAE label and API label. For example, "5w40" is an SAE label. So what does "5w40" stand for?
The "w" in "5w40" represents winter, and "5w" represents the viscosity of engine oil under low temperature conditions.
As we all know, under low temperature conditions, engine oil will thicken and become less fluid, which will affect the lubrication performance of the engine oil. Therefore, under low temperature conditions, it is necessary to choose an engine oil with a thinner viscosity to ensure good fluidity. The number before "w" represents the viscosity of the engine oil at low temperatures.
So how to identify this viscosity index? Generally, you can subtract 35 from the number in front of w, which is the minimum temperature suitable for modified engine oil. For example, 5w means it can be used in conditions as low as -30°C. This "5" represents the freezing point temperature. The smaller the number, the stronger the fluidity under low temperature conditions.
"40" is an indicator of the high temperature resistance of engine oil, representing the kinematic viscosity of the engine oil at 100°C. The higher the number, the higher the viscosity and the stronger the ability to withstand high temperatures.
The thinner the oil, the better, right?
The viscosity of engine oil we see at normal temperature does not represent its viscosity at high temperatures, nor does it represent its viscosity at low temperatures. The viscosity of engine oil changes with temperature. High-quality engine oil should have a viscosity that can still lubricate various components at high temperatures and still have good fluidity at low temperatures.
The viscosity of high-end engine oil is relatively low, but it does not mean that the thinner the oil, the better. Instead, refer to the instructions and choose the most appropriate engine oil according to the manufacturer's regulations on oil viscosity to achieve the best results.
Does engine oil become thinner with use or thicker with use?
Engine oil becomes thinner first and then thickens. Because most engine oils contain viscosity index improvers, when sheared for a long time, the viscosity index improvers will be sheared by the shear force and lose their original viscosity, causing the viscosity of the oil to decrease to a certain extent; a period of time After a while, due to the oxidation of the oil, a large amount of sludge and some impurities are produced, which are dispersed in the oil by the detergent and dispersant, causing the viscosity to increase.
The above introduces the meaning of 5w-40 to everyone. When choosing engine oil, many people do not know how to choose, and sometimes they misbelieve what others say, leading to a series of problems. In fact, generally if you choose according to the manufacturer's regulations on engine oil viscosity, there will be no problems. Even if it is not the best performance, it will be the most suitable.