Every automobile owner understands the importance of keeping the engine lubricated. Part of this job involves topping up engine oil when the level goes down. And when doing this, many people wonder if mixing different motor oils is safe.
Although car manufacturers and experts advise against mixing different oils, many car owners do so without causing harm to the engine. However, mixing two incompatible oils can affect engine performance and cause engine damage.
So, can you mix 10w30 and 5w30 oils? In this article, you’ll know the difference between these two motor oils and if it’s possible to blend them. You’ll also discover safe ways to mix different oils.
Question: What is 10w30 Oil?
10w30 is a multi-grade motor oil best suited for heavy-duty engines sustaining heavy loads. 10w30 is ideal for warmer climates, thanks to its higher viscosity. 10w indicates oil’s viscosity in winter or when your engine is cold. It shows how well this oil will flow when it’s cold.
On the other hand, 30 indicates oil’s viscosity at higher temperatures. This oil is thicker and will stay in place, lubricating engine parts even after heat exposure.
Question: What is 5w30 Oil?
5w30 is a multi-grade motor oil suitable for light-duty gasoline and diesel engines. Its 5w viscosity means it is ideal for colder climates. The oil runs thin in winter, flowing smoothly to lubricate all engine parts.
While 5w30 can perform well in warmer climates, it’s more likely to break down in scorching temperatures. Use this oil if you live in an area experiencing long, cold winters. This will flow easily even when the temperatures go too low.
Question: Can You Mix 10w30 and 5w30?
Yes, you can. Mixing 10w30 and 5w30 oils won’t harm your engine, but they’ll perform well at operating temperature. These oils have a similar viscosity at operating temperature, allowing them to blend well.
However, mixing these oils at low temperatures will show an opposite reaction. 5w30 is thin, while 10w30 is thick at low temperatures. Thus, mixing the two oils when the temperature is at its lowest doesn’t give positive results.
10w30 is thicker than 5w30 and will do well in high temperatures. The number before the “w” indicates how the oil flows in winter. You can use this number to tell how thick or thin a motor oil is.
Thinner oils flow easily in low temperatures. Thanks to its low viscosity, 5w30 will penetrate through the engine parts faster. The cold temperatures, particularly in winter, won’t affect its viscosity.
On the other hand, thicker oils flow well in high temperatures or high engine loads. However, thicker oils will flow slower in cold weather, meaning lubricating the engine will take longer. That means 10w30 will take longer to pass through and lubricate engine components.
When you compare 10w30 and 5w30, you won’t notice the difference in time as they get absorbed into the engine. So, when you mix the two oils, they will flow at the same rate without affecting the engine’s performance.
If mixing the two motor oils doesn’t feel right, stick with one type that suits you. If possible, use the oil that your manufacturer recommends. You can check the best oil for your vehicle in your owner’s manual.
Answer: Downsides of Mixing 10w30 and 5w30
You can mix 10w30 and 5w30 without worrying about possible downsides. However, manufacturers recommend against mixing two different motor oils.
Additives in different motor oils may not blend well when mixed. Some claim that mixing motor oils puts the engine at risk of failure. They say that mixing 10w30 and 5w30 at low temperatures can cause a reduction in engine performance.
However, the possibility of engine failure or poor performance is nearly impossible. Many car owners have been mixing these motor oils without reporting poor performance or engine failure.
The only thing you should worry about is losing warranty coverage because of mixing motor oils. Check if your owner’s manual advises against mixing two different motor oils. If so, stick to the manufacturer-recommended oil.
Answer: How to Safely Mix 10w30 and 5w30
We’ve now answered the question: Can you mix 10w30 and 5w30? You also know what can happen if you blend the two oils. But how should you mix these oils to ensure better engine performance?
As a rule of thumb, always add the lightweight oil first, then top off with the heavyweight oil. In our case, pour 5w30 first into the engine and then add 10w30. This way, the two oils will mix and lubricate engine parts properly.
Some car owners add the two oils at once and run the engine for a few minutes. This method is safe and will allow the two oils to mix correctly. If you use this method, avoid filling above the topmost mark. Pour half of 10w30 and 5w30 into the engine first for better results. Then top off with your remaining 5w30 oil.
Answer: Tips for Mixing Motor Oils
These tips will help you mix two different motor oils and benefit the most from them.
- Consider the weight of both oils: The two motor oils should weigh the same or slightly differ. They won’t mix if there’s a huge difference in weight.
- Use an additive: Adding oil additive to your oil blend helps the heavier oil to flow faster and blend easily with the lighter oil. An additive will prevent engine wear and tear. But there’s one thing you should note. Always choose the right additive for your mixture to avoid causing engine damage.
- Check the oil level after mixing: The goal is to avoid underfilling or overfilling the oil in your engine. Add more motor oil mixture if the level is still low. If you’ve overfilled your engine with oil, locate the drain plug, loosen it with a socket wrench, and drain the excess oil.
- Avoid spilling oil on the engine: Spilling oil on your engine can ruin components like fuel injectors and the serpentine belt. Oil is combustible and can ignite on provocation, causing significant damage to your car. In the case of a spillage, use a rag or degreaser to remove the spilled oil.
Final Thoughts
Can you mix 10w30 and 5w30 motor oils? Yes, you can mix the two motor oils without causing damage to your engine. While these oils differ in viscosity in low temperatures, the difference is insignificant and can’t prevent them from blending.
Adding an oil additive can help the two different motor oils mix properly. However, always check your owner’s manual to know the manufacturer-recommended oil.