Does Motor Oil Evaporate?: Know Today!
Evaporation is the typical behavior of a liquid. It’s common to lose motor oil by evaporating. All liquids don’t evaporate in the same way. Water evaporates at room temperature. In contrast, the alcohol evaporates faster than water. Again, motor oil doesn’t evaporate as usually as other fluids. Thus, things are different for motor oil. If you need to drive your car daily, it must be a question, does motor oil evaporate? And how much harm it’s doing. In the article, we will dive deep into this.
Is it true that motor oil evaporates?
Yes, motor oil evaporates, but it evaporates only at high temperatures. The amount of evaporation while the engine is off is too low and not that noticeable. But it evaporates more while the engine is running or the oil is heated.
It’s not that your engine oil will not evaporate while resting in the engine, but the amount is too little. You don’t need to have concerned about evaporating motor oil while resting your engine. But if you drive the car too much or the engine’s temperature rises, the evaporation happens quickly.

When motor oil evaporates?
Motor oil doesn’t evaporate like water. If you drop some motor oil on the floor for 24 hours, it will not evaporate as water evaporates at room temperature. But in the car, it can evaporate. The cause is the temperature. Evaporating is typical behavior of almost every liquid.
But if you raise the temperature, the evaporation rate will increase. The same thing happens with the motor oil. The engine makes too much heat that can burn the motor oil. Only then motor oil starts to evaporate. The evaporation temperature of different motor oils can vary.
However, mostly motor oils start evaporating at around 100 degrees Celsius. From that temperature, you can notice evaporation.
Why does motor oil evaporate?
The vaporization of a liquid on its surface as it shifts from a liquid to a gas is known as evaporation. Different liquids have different ways of evaporation.
When the temperature starts to rise, the motor oil in the engine starts to act unstable. The lighter substances of the motor oil start to become gas. As a result, the evaporation process starts.
Due to high temperatures, the oil molecules become unstable and start becoming gas. The gas exits the engine from the crankcase ventilation.
Effects of motor oil evaporation.
Some problems can occur for excessive evaporation. But thick engine oil is the most common and harmful one. When the engine oil evaporates, the oil becomes denser. The light liquid evaporates faster than the molecules.
So in the engine, thick oil is left. This thick oil is not ideal for lubrication. Since viscosity is crucial for motor oil, viscous oil can’t ensure proper lubrication. Even it can make stuck the internal parts of the engine. The performance loss is a must while your motor oil is thick. It has an impact on the fuel economy also.
Moreover, less lubrication means more fuel burning, less mileage, decaying engine parts, and many other problems. A car engine needs more energy to use thick lubricated oil. So it’s a waste of energy also. Only liquefying the motor oil can help you from there. But that can cut your pocket. So, be aware of motor oil evaporation. It can cause some big issues.

How to stop motor oil from evaporating?
Well, stopping evaporation isn’t completely possible. But you can reduce the evaporation rate by following two ways. The first thing is using low viscosity oil while the motor oil is thick.
When the motor oil gets thicker, use some low viscosity oil to stabilize the oil viscosity. It can help lubricate the engine by maintaining the required oil viscosity level. But it’s costly, cause you need to buy more motor oil.
The other and most effective way is using synthetic oil as motor oil. Synthetic oil can resist heat, and the viscosity level doesn’t fall. So, using synthetic oil helps to reduce the evaporation rate.
Synthetic oil is a bit more costly than the other types of oil. But it’s a great advantage. It will reduce your chances of losing motor oil by evaporation if you switch to fully synthetic oil.
Does fully synthetic oil evaporate?
It does. But the rate of evaporation is pretty low. Other oils evaporate faster than synthetic oil. Synthetic oils can resist heat. That helps them to reduce the evaporation rate.
How long does motor oil take to evaporate?
Motor oil needs to be heated up to evaporate. At normal temperature, it’s not gonna evaporate. But after heating the engine and the oil, it starts evaporating.
In a petrol engine, it takes 15 to 20 minutes to evaporate, and in a petrol engine, around 20 to 30 minutes running is required to start evaporating in a diesel engine.
Should I change the oil when it starts evaporating?
It depends on the condition of the motor oil. Dip your dipstick in the oil and check the oil. If the oil is clean but thick, you can use some low viscosity oil to reuse the oil. In contrast, if the oil is thick and dirty, it’ll be better to change it. If your engine faces a lot of evaporation, your oil can be dirty soon.
Final words:
Almost every liquid evaporates over time. Motor oil is a liquid also. Likely, it’s common for motor oil to evaporate. But the evaporation system isn’t the same as other liquids. Due to high heat, motor oil starts to evaporate. If your question is, does motor oil evaporate? Then the answer is affirmative. Motor oil evaporates after time.
But heat is the main character to do the job. Due to evaporation, motor oil in the engine becomes thicker, and that causes a lot of problems. Less lubrication, performance loss, and less mileage are the most common issues due to oil evaporation. You don’t need to worry about motor oil evaporation if your car is on rest. But motor oil evaporation is a concern if you drive your vehicle regularly and your engine temperature is high enough. Try using synthetic oil instead of regular oil to reduce the evaporation rate. Or use low viscosity oil to reduce the thickness of your motor oil.