You are in the middle of the road trip, and the vehicle illuminates the check engine oil light. You get to the nearby shop, and all you can get is 5W30 oil, whereas your car engine uses 5W20. Or 5W20, whereas your car uses 5W30.

Many car owners have been caught up in this situation. And the biggest fear is damage to the engine components, which can cost you a new car engine. But what’s the worry about and both oils have a 5W grade which means they are formulated for lower temperatures? The fear comes with the last figures, 20 and 30. They can bring about a big difference.

But what if you use the same brand? Being of the same brand and the same grade doesn’t guarantee they can mix or cannot mix. The main concern is whether the engine will be affected or not. So, let’s get the correct answers in this article.

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Valvoline Extended Protection Full Synthetic Motor Oil SAE 5W-20 and 5W-30 5 QT
Extended Protection for Valvoline. SAE 5W-20 Full Synthetic is designed to function in the demanding circumstances of today’s engines. In order to prevent oil breakdown, it can withstand high temperatures 10 times better than industry norms. To reduce deposits and sludge.

What Do 5W20 and 5W30 Codes Stand For?

You have all come across these codes, the 5W20 or the 5W30. But what do they stand for? The SAE (Society of Automotive Engineers) lays the oil format. The first number, which is 5, stands for the lowest temperature viscosity below 0°C. The second is the letter W which stands for winter. Finally, the number after the letter is either 20 or 30, which stands for the highest temperature viscosity at 100°C.

5 5 Lowest temperature viscosity below zero degrees.
W W The oil is manufactured for winter use.
20 30 The highest temperature viscosity at one hundred degrees celsius.

The information above clearly indicates that 5W20 can operate better at lower temperatures than 5W30. On the other hand, 5W30 will do better in higher temperatures than 5W20.

Here Is What You Need to Know When Mixing 5w20 and 5w30 Oil

You can mix 5W20 and 5W30 oils. However, you must examine how the engine reacts after adding the mixture for lubrication. Ideally, choose the same brand and API service level to keep your engine safe.

But is it ok to mix 5W20 with 5W30?

As a rule of thumb, you may not get visible results. If your engine oil lamp has illuminated and you need to add the mixture and get to your destination, then you are good to proceed. But if you mix for engine performance or better mileage, you may get shocked. Learn why in the next paragraph.

What Happens If You Mix 5W20 With 5W30?

5W20 and 5W30 oils have different viscosity and differ in additive components. So, the oils will only partially mix to form one mixture. But the good thing is if you mix them for emergencies, the engine will not experience any negative effects.

What Happens If You Mix 5W20 With 5W30: image

Take, for instance, you mix both oils in an incompatible engine. Maybe your engine uses 5W30, which operates at higher temperatures. The mixture will not lubricate the engine well, which may result in overheating and quick wearing of engine components. The same may happen if you use the 5W20 oil. The 5W30 oil will be thicker to penetrate between some moving parts.

What Ratios Can You Mix?

If you are mixing the oils for emergencies, consult the user manual and note well the kind of oil you use. The recommended oil should be more than the incompatible oil you have decided to use.

For example, if your engine uses 5W30 oil, you can check the level in the engine and top up with 5W20 in a ratio of two parts, 5W30, and one part 5W20. On the other hand, if your car uses 5W20, you can use two parts, 5W20, and one part, 5W30.

Check the owner manual to confirm whether the manufacturer allows mixing both oils. If it’s permitted, confirm the correct ratio and drive your car until the next service. However, if it’s not recommended, flush the oil mixture and refill with the right once you get to your destination.

Can You Use 5w20 Instead Of 5w30?

5W20 engine oil has lesser viscosity compared to the 5W30. So, can you mix 5w-20 and 5w-30 in a 5W30 engine? The engine is designed for more viscous oils, and the 5W20 oil may not lubricate it well, especially during high temperatures.

How would the oil perform? The oil would be too thin to coat the engine components against rubbing each other. This may result in higher friction, and the components may wear and tear fast.

The only way you can use 5W20 oil in a 5W30 engine is by mixing them. And mixing both should be permitted by the manufacturer. Else, you could expose your engine to slow death.

Wanna know more about use 10w30 instead of 5w30?

Can You Use 5w30 Instead Of 5w20?

Using 5W30 oil in a 5W20 engine isn’t wise because the engine is designed for a lower viscosity than the oil. As such, the oil would be too thick to seep through various moving parts. The engine components may wear and tear quickly, and overheating can happen. Additionally, you can experience oil starvation.

Can You Use 5w30 Instead Of 5w20: image

A 5W30 oil may be safer to use in a 5W20 engine if mixed well. However, you should first confirm if the manufacturer has permitted adding multiple oils with different viscosity. If not allowed, then you should do it for emergency purposes only.

Main Differences Between 5w30 and 5w20?

The truth about 5W20 and 5W30 oils is that they are both manufactured for winter use. However, the 5W20 can operate at lower temperatures than the 5W30. This makes it ideal for extremely cold temperatures because it can penetrate and lubricate contracted metal components well. However, when it gets hotter, 5W20 may not be much effective; it will be too light for the expanded engine metallic components.

5W30 oil, on the other hand, is ideal for hot temperatures. It’s heavy enough to lubricate the heated parts and prevent excessive friction. However, the oil may be too heavy in cold temperatures for the engine parts. This prevents it from seeping between the moving parts and lubricating them to avoid friction.

At normal operating temperatures, the 5W20 oil works best to save fuel. It’s thin enough to lubricate the moving parts without strain. If you live in tropical regions, you can use 5W30 since it doesn’t get extremely cold during winter.

Frequently Asked Questions (FAQs):


Is Mixing 5W30 With 5W20 Bad?

Mixing 5w30 with 5w20 isn’t bad for the emergency. But what happens if you mix 5W20 with 5W30? The oils have different viscosities. Having different viscosities mean they cannot completely mix to form one mixture.

This makes it harder for the incomplete mixture to lubricate the car engine. If you decide to mix the two for an emergency, first note well the type of the engine and add the recommended oil type in a higher ratio.

Mixing at least two parts of recommended oil with one part of unrecommended oil will help save the engine components from friction.


Can You Mix 5W20 and 5W20 Synthetic Oil?

Yes. In fact, there is no proven risk of mixing 5W20 oil with a 5W20 synthetic oil. But what would be the result in terms of engine performance? They won’t boost the engine performance or increase the gas mileage. Instead, it will normally work as the other oils.

Can I mix 5W30 with 5W20 synthetic? Yes. They will perfectly mix but be extra keen to note how the engine reacts. Also, check the information for mixing synthetic oil weights because some may have very high viscosity to match with lower grades.


Can I Use 5W-30 For Diesel?

Yes. 5W30 is a motor oil commonly used in light-duty diesel and petrol engines. The oil is manufactured as a multi-grade oil, meaning it ranges from lower viscosity of 5 to higher viscosity of 30.

This makes it ideal for diesel engines. However, you should confirm with the manufacturer before using because different grades may be available in the market, including counterfeits.


Is 5w20 Good for Diesel Engines?

Yes. 5W20 oil is manufactured to start various engines at low and moderate temperatures. However, if you need better 5W20 oil for your diesel engine, go for a fully synthetic grade designed to withstand high pressure and temperature.

These oils work best in both gas and turbo-diesel engines. Always visit a trusted dealer for the original oil to avoid servicing your engine with low-quality oils.


How Do I Know If My Car Takes Synthetic or Conventional Oil?

The most straightforward way to know whether your car uses synthetic or conventional oil is to refer to the user manual. Some manufacturers may allow either two or just one. For instance, most modern vehicles take either regular or synthetic oils.

Note that in some cases, the car may drive well with an incompatible oil, but you won’t drive for long without breaking down. Always prefer to use the recommended oil for better engine performance and lifespan.

Final Verdict

Mixing 5W20 and 5W30 motor oil is good if the manufacturer has allowed it. Note that the oils have different viscosities, so they won’t completely mix. The most worrying fact about mixing the two is that you can have your car warranty nullified if the engine breaks down. However, if you are in an emergency, you can mix the two and drive to your destination instead of driving the car with low-oil levels.

Remember to test drive and note how the engine reacts to the mixture before taking a long journey. I wish we have answered all your questions, like can you put 5W30 in a 5W20 engine? Will 5W30 hurt a 5W20 engine? What to do if I accidentally mixed 5W30 and 5W20? And others. If you have more questions, kindly comment below. All the best!