Engine oils have become lighter. The popular grades include 0W-8, 0W-12, and 0W-16 because modern engines have an objective to conserve fuel and reduce emissions. Less viscous oils offer less resistance to the engine, allowing the moving parts to work more smoothly.
However, what does the number mean? The first number, that is with W, means the flow rate of the oil at low temperatures, while the second number means the viscosity of the oil when the engine is hot.
Today’s ultra-low viscosity oils are formulated using top-quality synthetic base oils and additive technology to offer the protection required by the current engines. At Fubex Lubricants, we ensure that you get the best engine oil that keeps your engine healthy and minimizes its wear. 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 ultra-low-viscosity oils and choosing the right grade can help reduce friction, improve fuel efficiency, protect engine components, and support reliable engine performance.”
Keep reading to explore why these oils matter and where they fit in modern engines.
What Low-Viscosity Engine Oil Means
Low-viscosity engine oils like 0W-16, 0W-20, 0W-30, and 5W-30 have been developed to flow easily, especially in cold conditions. Thus, it allows the oil to get to the vital parts of the engine in a short time, making it easier to reduce friction during the startup of the engine when it is important to have the lubrication.
What do these numbers really mean? For instance, 0W or 5W shows the flow of the oil in cold weather. In this case, ’W’ stands for winter. The second number like 16, 20, 30, or 40 shows the viscosity of the oil at operating temperatures of the engine.
Low-viscosity oils can help reduce friction and may improve fuel efficiency. However, the right oil grade depends on the engine’s design and the manufacturer’s requirements. Always check your vehicle owner’s manual and use the recommended viscosity and specification.
Low-Viscosity Oils and Fuel Efficiency
One of the most important reasons why modern cars use oils with low viscosity is their ability to increase fuel economy. Thanks to low viscosity, engines do not require extra effort from the driver in order to move all the internal elements. However, does the lowest possible viscosity always guarantee good results? No, it does not. All of this depends on the specific engine and oil required for it.
Some engines are capable of running on ultra-low viscosity oil, such as 0W-16 oil, whereas others can run on 5W-30 or 5W-40 oil.
Excessive viscosity or insufficient viscosity of oil in the engine affects both protection and performance of the engine itself. This is why you should never pick engine oil only according to its viscosity. It is important to refer to the specification required by your car.
Viscosity and Volatility
Lowering lubricant viscosity can help reduce friction, but it can also increase volatility. Volatility means how easily the lighter parts of the oil can evaporate when exposed to high temperatures.
Modern engines can reach very high operating temperatures. The lubricant will lose some of its lighter components due to evaporation at such temperatures. This results in thickening of the oil, which leads to increased friction, thus reducing some of the energy savings from the use of low viscosity oil.
There is also a minimum HTHS viscosity requirement, which regulates the volatility of the oil. The reduction of the number of additives might help decrease the volatility of the oil.
That is why lubricant manufacturers need to find the right balance between low viscosity, low volatility, and strong engine protection. The goal is to develop oils that flow easily while still providing reliable protection at high temperatures.
Who Actually Uses 0W-8 Today?
You might be wondering, who actually uses 0W-8 engine oil today? Some models of Toyota and Mazda hybrid cars, as well as some small engines, are intended for use with 0W-8. Such engines are manufactured to work with this type of very thin oil in order to increase fuel efficiency and decrease pollution levels.
On the other hand, 0W-8 is not always the right choice for an engine. In case your owner’s manual recommends 0W-8, you need to follow it.
Always check the recommended specification before switching oils. Protection, performance and efficiency could be affected by an oil that does not suit your engine.
Base Stocks Add Complexity
Making effective low-viscosity lubricants is not as simple as just using thinner oil. The base stock also assumes an important role in the development of ULVOS. The base stocks need to be highly refined in order to have low viscosities, high viscosity indexes (VI), and low volatility to allow for easy flow while still being effective in lubricating the engine.
However, one more difficulty exists – availability and cost of the products. As the industry moves toward ULVOS, the availability and costs of the base stocks will play an important role.
At the moment, there should be enough Group III base oils to meet the demand for SAE 0W-16 and 0W-20 oils. However, it is still uncertain whether there will be enough very high-VI and PAO base stocks for the growing demand for ultra-low-viscosity lubricants. If the supply is constrained, investment costs for the producers will be even greater.
Sometimes, things can become even more complex due to the OEM specifications being not identical at all times. Depending on the requirements, manufacturers will apply different ratios of Group III, high-VI Group III, PAO, and ester base oils.
The idea is to find the optimal ratio which would guarantee the necessary performance and still keep the product affordable and reliable to supply.
Why Additives Matter in Engine Oil
Engine oil is more than just base oil. A big part of its performance comes from the additives mixed into it. These additives give the oil special properties that help protect the engine and keep it running smoothly.
Wear Protection
Anti-wear additives help reduce contact between moving metal parts. This can lower wear and help protect important engine components.
Cleanliness
Detergent additives help keep engine parts clean by reducing the buildup of deposits and sludge.
Oxidation Protection
Oxidation inhibitors help the oil fight heat and oxygen, slowing down breakdown. That prevents the oil from breaking down too fast.
Corrosion Protection
Corrosion inhibitors help protect engine parts from rust and chemical damage caused by moisture and other contaminants.
Friction Reduction
Friction modifiers help reduce resistance between moving parts. This can help the engine run more efficiently.
Viscosity Stability
Viscosity modifiers play an important role to ensure the oil has the correct viscosity under different temperatures in the engine. This is particularly true for the current engine, which operates at various temperatures.
Therefore, the engine oil serves many functions other than acting as a lubricant. With the right formulation, the engine oil can reduce wear, minimize deposits, resist heat, prevent corrosion, and increase efficiency.
Risks of Choosing the Wrong Oil
Selecting engine oil is more than just picking an SAE number such as 0W-20 or 5W-30. Inadequate selection of engine oil may lead to many different complications, particularly if the selected oil fails to fulfill the engine manufacturer’s specifications.
- Lower Protection: When the engine is under high load or operates at a high temperature, and there is low viscosity of oil in it, the film of oil cannot be thick enough between the surfaces of the moving metal parts of the engine. This leads to increased friction and wear.
- Wear of Turbocharger Components: In case of turbocharged engines, including GDI engines, the temperature regime of their operation can be quite high. The use of inappropriate oil specification will result in higher deposits and increased wear of turbocharger components.
- Problems With Warranty Claims: Nevertheless, the use of inappropriate types of engine oil can cause problems in case of problems related to warranty claims in future.
- Shorter Oil Change Intervals: Some ultra-low viscosity oils require specific oil change intervals depending on the conditions of its use in the vehicle.
- Problems With Seals: In some old engines, seals may not cooperate appropriately with ultra-low viscosity oils.
The simple rule is: don’t choose engine oil based on viscosity alone. Always check the vehicle manufacturer’s recommended grade and specification.
Choosing the Right Oil: A Simple Decision Flow
Not sure which engine oil to choose? It does not have to be complicated. Just follow these simple steps:
Check Your Owner’s Manual
Start by checking your owner’s manual or under-hood label. It will show the recommended SAE viscosity grade and the required specification, such as API, ACEA, or ILSAC. If it recommends 0W-8, use 0W-8 that is approved for your vehicle.
Check If More Than One Grade Is Allowed
There are engine types that allow for multiple viscosity grades, like 0W-16 or 0W-20 oils. When there is a possibility of choosing which type of oil to use, it is important to think about where you live and drive. Sometimes it can be beneficial to choose a thicker oil or a thinner oil.
Match the Required Specification
Do not look at viscosity alone. Make sure the oil clearly meets the required API, ACEA, or ILSAC specification for your engine. These specifications help show that the oil meets the required performance standards.
Consider the Engine’s Age
Older engines have more wear and larger clearances between moving parts. So, an ultra-thin oil isn’t necessarily the best way to go or 5W-40. Depends on the engine manufacturer.
Always follow the vehicle manufacturer’s recommendations first. If several options are approved, then choose the grade that best suits your engine, climate, and driving conditions.
Final Takeaways
Ultra-low-viscosity engine oils like 0W-8 and 0W-12 are becoming an important part of modern engine technology. This way, they can minimize friction, provide fuel economy, and facilitate the reduction of pollution, however, thin oil does not mean good oil for all engines. The proper selection of the lubricating fluid depends only on the requirements of the car maker, the type of the engine, and the operating environment.
As engines become more sophisticated in 2026 and later years, selecting the proper oil is as important as selecting the low viscosity oil.
FAQs
Q1: Is 0W-8 engine oil too thin to be safe?
Not if your vehicle is designed for it. 0W-8 is made for certain modern engines and provides the required protection while helping reduce friction. Always use it only when approved by the manufacturer.
Q2: Can I use 0W-8 or 0W-16 in an older car to improve fuel economy?
Only if your vehicle manufacturer recommends it. Using thinner oil than required may reduce friction, but it can also affect engine protection. Always check your owner’s manual first.
Q3: Can using the wrong engine oil affect my warranty?
It can cause problems if the oil does not meet the manufacturer’s required specification and an engine failure occurs. Use the recommended oil and keep your receipts and service records.
Q4: How can I tell if my car needs an ultra-low-viscosity oil?
Check your owner’s manual or oil filler cap for the recommended viscosity grade. If it lists 0W-8 or 0W-16, use that grade or another option specifically approved by the manufacturer.
Q5: Is it worth paying more for premium engine oil?
Premium oil can be useful when your engine requires specific performance standards or low-viscosity grades. However, the most important thing is choosing oil that meets the manufacturer’s required specification.
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.
