Do you know the difference between oil weights? If not, don’t worry! We’ve got you covered. This post is going to answer your burning question: Can you mix 5w20 and 5w30?
The short answer is YES, you can mix 5w20 & 5w30 given that they’re from the same brand and API.
The below explanation will let you know why we can do that.
Understanding Viscosity of Oils
Oil weight refers to a measurement of viscosity, which is a lubricant’s resistance to flow at a given shear rate. Viscosity matters because it dictates an oil’s ability to protect your engine against wear and tear. Viscosity is also what helps an oil clean your engine’s surfaces.
We’ll start with the numbers. The 5w20 is the designation of a viscosity that ranges between 10,000 cSt (centistokes) to 14,000 cSt (centistokes). The 5w30 is the designation of a viscosity between 15,000 cSt (centistokes) to 20,000 cSt (centistokes).
How Are These Two Oil Viscosities Different?
The 5w30 designation refers to the base oil viscosity, which is 10% thicker than the standard 5w20. For example, a 5w30 motor oil has an API GL-5 rating, but the same base oil could have an API SN GL-4 rating. These are just examples since there are other classification systems used in motor oils, but they’re common ones.
Even though they’re called “w” weights, these numbers don’t actually refer to weight at all. Instead, the w stands for winter. “Winter” motor oils are designed to handle longer periods of cold weather and protect against engine wear from starts and stops in cold weather. So basically, the “w” doesn’t directly correlate with weight.
In the case of an engine that uses a mix of oil weights, the 5w20 and 5w30 may show up in different percentages at different times. For example, an owner may take their car to their local mechanic for an oil change and ask for a specific weight. The mechanics will actually weigh the oil and give you a recommendation based on your engine’s needs. If you need anything over 7 quarts (7 liters), you can tell them to use 5w30 instead of 5w20.
What 5W20 and 5W30 have in common is that they have the same viscosity in winter.
Why You Should Use 5W20 & 5W30 Oils
Below are some of the benefits of using 5w20 and 5w30 oil:
- Performance: Motor oil increases your engine’s performance. Higher flow allows your engine to flow cooler, which reduces wear on internal engine components.
- Improved Fuel Economy: 5w20 and 5w30 oils are formulated with multiple additives that help improve fuel economy by lowering emissions.
- Smoother Running: Motor oils are used in your engine’s pump, which helps reduce friction.
- Reduced Wear & Tear: Reduce engine wear and tear with motor oil. This improves the efficiency and overall performance of your car.
- Better Protection: Motor oils protect internal engine components from wear and tear by preventing corrosion, offering lubrication for moving parts, and more.
Can You Mix 5W20 and 5W30?
Yes, you can top up your 5W20 with 5W30 or the other way around. Keep in mind that it’s probably not a good idea to mix the two oils, because 5W30 is thicker than 5W20 but the mixture won’t harm the engine anyway.
It’s generally accepted that mixing different weights is better than using one weight for your engine. The reasons are that it’s better for your car to have a wide range of viscosities available. Different viscosities provide different cleaning and lubrication abilities, which is important for keeping your engine clean and problem-free. What’s more, this prevents the thinning effect that happens when using a thin oil for too long.
Are There Any Benefits of Mixing Oils?
Not really. Some people may benefit from mixing oils, but this is only a temporary fix. Changing the amount of base oil in your engine will require a new oil filter and an oil change. So if you’re mixing 5w20 with 5w30, you’ll probably need to change the oil again in just a few thousand miles.
To conclude, you can mix 5W20 & 5W30 provided that they’re from the same brand and API. If you want to come up with your own oil mixture, just check the oil number of the two oils. For example, if they’re 5W-30 and 10W-30, then you can use 80% of the amount of the 5W-30 and 20% of 10W-30.