Can I Use 5W30 Instead of 5W20

Can I Use 5W30 Instead of 5W20?

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Whether you’ve just bought a new car or you’ve had it for a while, thinking about which type of oil to use for your auto can lead to a lot of confusion. In fact, this question of “Can I use 5W30 instead of 5W20?” has been asked by so many motorists in most automotive forums. The reason for this, however, is because these two oils are the most commonly used by most vehicles. So, if you’re not aware of their difference in viscosity, you might end up using them on the wrong engine leading to deadly results.

Now, engine oil is a very important addition that impacts your car’s performance. It’s like the lifeblood of your engine without which your auto will be dead. Its main purpose is to lubricate your engine’s moving parts to prevent them from constant friction caused by metal-to-metal contact. In addition, oil aids in cooling the engine while still flushing out sludge from the engine’s cylinders to boost the engine’s efficiency. But, despite being a crucial part of your engine’s performance, choosing the right oil for your specific engine is an absolute must. So, in this short guide, we will discuss the main difference between 5W30 and 5W20 and later answer the question of which oil should suit your specific situation.


But First, What Do the Numbers Mean?


Now, to keep your auto’s engine in good shape, you have to change the oil at the right time. In most cases, you’ll have to choose between 5W30 and 5W20. That’s because these two oils work best both in cold and hot temperatures. In the world of automotive, engine oil is determined by its viscosity rating or rather its resistance to flow. For instance, honey and molasses are thicker than water. That means the former has a higher viscosity rating than the latter.

The principle is used to determine the viscosity rating of different types of engine oils. These oils are determined by numbers, called viscosity indices, that can range from 0, 5, 10, 15, 20, 25, 30, 40, 50 to 60. Now, in the case of 5W30 and 5W20, several numbers are visible. First, there’s the 5 which represents the viscosity rating of the oil in cold or frosty weather conditions. You see, in the past, driving cars in winter conditions wasn’t an issue as most cars didn’t have the 4WD capabilities. However, with most modern SUV vehicles being 4×4s, choosing oil with precise winter viscosity has become an absolute must.

Now, next to the 5 is a letter “W” which stands for “Winter”. The numbers that come after the “W”, in our case 20 and 30, represent the weight of the oil in warmer temperatures. In this case, these numbers will represent the weight of the oil when the engine heats up.


So, Which Oil is Best For;


Cold Temperatures

Now that we’ve explained the meaning of each number contained in your oil’s viscosity index, our next focus is to discuss which oil should be used on which season or temperature. The best thing about most engine oils today is that they have multigrade formulas. This gives their viscosity the ability to change in relation to temperature fluctuations. This is quite different from single-grade oils that are only designed for a specific temperature.

For instance, if you happen to use your car in extremely cold regions, you’ll need to use less viscous oil. When using thin oil in freezing temperatures, the oil will experience less drag and friction allowing it to flow freely to the furthest moving parts of your engine. Since the 5W20 oil is considered to be thinner, it’s hence the best alternative when it comes to freezing temperatures. The thin nature of this oil will allow it to flow perfectly without being interrupted by cold temperatures. This will allow it to lubricate all moving parts leading to optimal fuel efficiency to your auto.

However, as your engine heats up, the 5W20 oil automatically begins to lose its viscosity. As temperatures get hotter, this oil eventually breaks down exposing your engine to rapid wear. At this point, the 5W30 automatically becomes the more preferable oil.


Hot Temperatures

When it comes to warmer temperatures, the 5W30 is a clear winner. That’s because this oil is characterized by higher viscosity that’s denoted by the number 30 in its formula. What this means is that this oil will have more drag when flowing allowing it to last longer in your engine’s components. The longer it will take in your engine, the more protection this oil will offer to your engine in hot climates.

This is way different from 5W20 which tends to break down in hot temperatures. However, in cold temperatures, the 5W30 will be unlikely to excel. That’s because it has more drag that prevents it from flowing quickly to all engine components within a short period. This means that fuel efficiency will generally be compromised. Also, you’re likely to experience engine delays and hiccups whenever you start your engine in cold temperatures.

As you can see, the number that comes after “W” has a lot of significance as it represents the weight of the oil in warmer climates. So, as this number increases, then it means the viscosity of your oil will also be higher. In our case, the 5W30 is hence thicker and more viscous than its counterpart the 5W20. This means that the 5W20 is the perfect engine oil for cold temperatures while the 5W30 is tipped to thrive in hot climates.


5W30 Vs. 5W20: Effects on Gas-Mileage


In our discussion, we’ve mentioned that the 5W20 provides a thinner barrier of protection in cold temperatures. The 5W30 oil, on the other hand, is more preferred in hot climates as its high viscosity prevents it from breaking in high temperatures. The low viscosity rating of 5W20 allows it to lubricate engines quite fast in cold temperatures leading to enhanced fuel efficiency. But, according to most professionals, including most automotive forums, this fuel efficiency comes at a great cost.

How is that? You see, when it comes to high temperatures, the 5W20 automatically becomes less useful as it can’t stand the heat. As a result, your engine may suffer a lot of abuse that can lead to rapid wear. This rapid wear caused by friction can lower your car’s mileage if you’re not careful. For that reason, the 5W30 automatically becomes the best oil for improving the mileage as it doesn’t break when exposed to high temperatures.



So, are you still wondering which oil to pick between 5W30 and 5W20? Well, the answer lies in your car’s owner’s manual. In most cases, it’s highly recommended that you peruse through your manual to identify the perfect oil for your engine.

However, if you’re unable to identify the right oil, then you don’t need to worry. The 5W30 can easily become your perfect pick due to its ability to resist breakage when exposed to high temperatures. So, with that said, we believe that this guide has given you the answer on whether to use 5W30 or 5W20 to lubricate your engine.

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