Have you ever noticed that your engine seems to lose oil even when there is no visible leak? Oil evaporation could be one reason. Engine oil doesn’t simply reduce friction. It protects the engine parts from heat and wear. But if the engine gets very hot, some of the lighter elements in the oil can evaporate.
Modern engines can produce a lot of heat. They have turbochargers and direct fuel injection. In these conditions, the volatile oils can evaporate faster. This can lower the level of oil, and deposit more viscous oil that does not flow as easily.
So what is Noack volatility and why does it matter in engine oils? It is useful to show the resistance to evaporation of engine oil at high temperatures. We at Fubex Lubricants make sure that you have the best engine oil that protects your engine while lessening the wear and keeping it running smoothly. Do you require assistance in finding the ideal engine oil to meet your needs? Contact us at +971 50 544 9614 for expert advice.
Awais I., Sales Director, says, “Understanding Noack volatility can help reduce oil consumption, protect engine components from heat and wear, maintain proper oil viscosity, and support reliable engine performance for longer.”
This article explains what the Noack test does, why oil volatility is important and what impact oil volatility can have on engine performance, fuel economy and protection.
Key Takeaways
- Noack volatility shows how much engine oil evaporates when exposed to high temperatures.
- The lower the Noack, the less the oil evaporates and the better it can protect at high temperatures.
- High oil volatility can cause oil consumption, deposits. Low-volatility oils cushion pistons, rings, turbochargers and other engine parts.
- Recommended viscosity and oil specifications for your engine.
- Noack volatility is one of the factors to take into account when choosing an engine oil.
What Is the Noack Volatility Test? (ASTM D5800)
The Noack Volatility Test, also known as ASTM D5800, measures how much motor oil evaporates when exposed to high temperatures. It shows the percentage of oil lost by evaporation. The smaller the percentage the less the oil will evaporate and the longer it will keep its proper thickness and protection when the engine gets hot.
How Does the Noack Test Work?
The test follows a controlled process:
- A measured sample of motor oil is placed in a test machine.
- The oil is heated to 250°C (482°F) for 60 minutes.
- Dry air is passed over the oil during the test.
- Some of the lighter parts of the oil evaporate and leave the sample.
- The oil is weighed again after the test.
- The difference in weight is used to calculate the percentage of oil lost through evaporation.
This percentage is due to Noack volatility. The lower the result the better the oil is in resisting evaporation at high temperatures.
Volatility
Volatility refers to how easily the lighter parts of engine oil evaporate when exposed to heat. This matters because excessive evaporation can increase oil consumption and affect the oil’s ability to protect engine parts.
With the volatile parts of the oil evaporated, only the heavier ones are left behind. These factors will tend to thicken the oil and decrease its flow. This leads to more friction and fuel consumption.
The Noack Volatility test is a measurement of how much oil evaporates at high temperature. A lower Noack volatility number means there is less oil that evaporates, thus maintaining the oil level.
Why Volatility Matters
When motor oil evaporates, it can cause several problems in the engine:
- Higher oil consumption
- Thicker remaining oil
- More harmful deposits
- Less engine performance and protection
7 Effects of Oil Evaporation
The evaporation of oil can have an impact on the engine performance, fuel consumption and life of the engine. There are a few problems with too much oil evaporation.
1. Increased Oil Consumption
When engine oil evaporates, the oil level drops faster than normal. This means drivers may need to add oil more often.
Possible Effects:
- More frequent oil top-ups
- Higher maintenance costs
- Low oil levels that can cause serious engine damage
2. Engine Deposits and Sludge
Some of the oil fumes may burn inside the engine and carbon buildups. Such buildups may develop inside the pistons or other parts of the engine. They will be the reason for sticking piston rings and low engine efficiency.
Possible Effects:
- Lower fuel efficiency
- Harder engine starts
- More engine wear over time
3. Turbocharger Damage
Turbochargers run at very high temperatures. Oil evaporation may leave carbon deposits on turbocharger parts. These deposits can build up over time and affect turbo operation and damage the bearings.
Possible Effects:
- Lower turbocharger performance
- Bearing damage
- Expensive turbocharger repairs or replacement
4. Oil Thickening
It thickens due to the lighter components of the oil having evaporated. When oil thickens it doesn’t flow easily through an engine.
Possible Effects:
- Poor lubrication
- More friction
- Higher fuel consumption
- Faster engine wear
5. Emission System Problems
Oil vapors can enter the exhaust system and affect parts such as catalytic converters, diesel particulate filters (DPF), and exhaust gas recirculation (EGR) systems.
Possible Effects:
- Higher emissions
- Reduced emission system performance
- Expensive repairs
6. Shorter Oil Life
Evaporation of the oil can lead to alteration in the composition of the oil. With the evaporation of lighter components, the oil will no longer be able to give the same kind of protection.
Possible Effects:
- Shorter oil life
- More frequent oil changes
- Higher maintenance costs
7. Lower Fuel Economy
The oil may become viscous due to evaporation, thus leading to an increase in the resistance of movement in the engine parts. Therefore, the engine will have to work hard and consume more fuel.
Possible Effect:
- Lower fuel efficiency and higher fuel costs
Low volatility motor oil helps to lower oil loss and provide better engine protection at high temperatures.
Why Modern Engines Demand Low-Volatility Oils
Today’s engines are smaller, lighter and more powerful than older models. They also work at higher temperatures and pressures. Turbocharging, gasoline direct injection (GDI), variable valve timing and hybrid systems can all add heat and stress to an engine.
Because of these conditions:
- Low-quality oils can evaporate more quickly.
- Evaporated oil can leave deposits around turbocharger bearings and piston rings.
- The oil may also be getting thicker as the lighter parts of the oil evaporate.
- Heavier or lighter oil can increase wear on the engine, especially during cold starts and heavy loads.
How to Choose the Right Low-Volatility Oil
When choosing a low-volatility engine oil, look for these points:
- A Noack volatility value below 13%
- ASTM D5800 listed products
- Test results from a trusted oil manufacturer
Some oil manufacturers provide Noack test results comprehensively in the technical data. The information may be helpful in estimating the evaporation resistance of different types of oils.
The use of a turbocharged truck, sport car, or working machine requires you to pay attention to low oil volatility. An oil which is resistant to evaporation will help to maintain the right oil level.
High vs. Low Noack Volatility
Noack volatility shows how easily engine oil can evaporate at high temperatures.
Oil With High Noack Volatility
- Evaporates faster, so you may need to add oil more often.
- Can leave carbon deposits that may reduce engine life.
- Makes the remaining oil thicker, which can reduce proper lubrication.
- Can affect turbochargers and emission system parts.
Oil With Low Noack Volatility
- Reduces oil consumption.
- Helps protect pistons, piston rings and turbocharger bearings.
- Helps engine run more efficiently.
- Can help cut emissions.
- May help extend oil life between oil change intervals.
Final Takeaways
Noack volatility is a technical term, but it is important to engine oil performance. Highly volatile oil is easier to evaporate and increases oil consumption, leaving deposits and reducing engine protection. Low-volatility oil helps keep the engine at the proper oil level, wears less and performs better in high heat.
If you want reliable engine protection, always consider Noack volatility along with the oil’s viscosity and other important specifications. Fubex Lubricants is committed to offering quality lubricants that help to ensure smooth and reliable engine performance.
FAQs
Q1: Does low Noack volatility reduce oil consumption?
Yes. Oil with lower Noack volatility evaporates less, so the engine loses less oil and needs fewer top-ups.
Q2: Can I switch from mineral oil to synthetic oil?
Yes. Most modern engines can use synthetic oil, but you should always check your vehicle owner’s manual for the recommended oil type and viscosity.
Q3: Is Noack volatility important for trucks and industrial engines?
Yes. Trucks and industrial machines often run for long hours and at high temperatures. Low-volatility oil can help reduce evaporation and provide better protection.
Editor-at-Large
A passionate writer in the lubricant industry, Awais Iqbal has been covering oils, greases, and industrial fluids since the start of his career. At 25, he’s already written for blogs, catalogs, and brand guides across the UAE. Awais’s insights help companies connect with their audience, and his clear, helpful writing style is trusted by brands in the region.
