Can I Use 5W30 Motor Oil Instead of 5W20?


If fuel is the lifeblood of your vehicle, then motor oil is its red blood cells. As such, you must make sure that you choose the right type of oil if you want to ensure the best performance. Furthermore, each oil type functions differently, as you will soon discover.

A lot of drivers wonder if it’s all right to use 5W30 instead of 5W20. As similar as they may appear, each oil is in fact quite different from the other. You could potentially harm your engine by using 5W30 in place of 5W20.

Oil Types Explained

Before you take your vehicle in for an oil change, you should first understand the differences in oil types. The most commonly used types of oil are conventional and synthetic.

However, your car doesn’t necessarily have to conform to these two types, as this largely depends on the condition of your vehicle. Let’s take a moment to explore the various oil types so you’ll know what kind should be used in your car.

Conventional Motor Oil

Also known as regular motor oil, conventional motor oil is used in most vehicles. It is best served for engines that have a simplistic design, with lower to average mileage and normal driving habits.

While it’s true that conventional motor oil needs to be changed more often than synthetic oil, it is also much cheaper to do so.

Designed for engines with less wear and tear, it is better that you start out using conventional motor oil. After your vehicle has gained more miles, you should switch to a motor oil designed for higher mileage. Speak with a trusted mechanic if you’re unsure about when to transition.

Full Synthetic Motor Oil

Full synthetic motor oil consists of properties that make it a better choice for varied temperatures. It is designed to accommodate engines that are more complex in their construction, such as those with high-performance capabilities.

Most modern vehicles require full synthetic motor oil due to the ever-evolving nature of cars and their engines. If you prefer to drive as long as you can between oil changes, this is the type of oil for you.

Related: Difference Between Synthetic Oil And Conventional Oil

Synthetic Blend Motor Oil

Synthetic blend is a type of motor oil that lies between conventional and fully synthetic. In fact, the synthetic blend contains both conventional and full synthetic motors oils.

What’s more, the synthetic blend is ideal for drivers who are transitioning from conventional motor oil to full synthetic motor oil.

It’s no secret that full synthetic motor oil is more expensive than conventional motor oil. As such, buying a synthetic blend is a great way to get the benefits of full synthetic without paying the higher price tag.

High Mileage Motor Oil

Lastly, there’s high mileage motor oil. Designed for engines that have surpassed 75,000 miles, you should use this type of oil if you want to give your vehicle better protection from things like burn out and oil leaks.

High mileage motor oil provides greater flexibility in your engine’s internal seals, so it’s a great fit for vehicles that are more prone to wear.

There is both conventional and synthetic high mileage motor oil available, so you can get the best type based on your vehicle’s needs.

Do I Have to Wait Until I Reach High Miles to Use High Mileage Oil?

Actually, you can use high mileage motor oil in vehicles that are new and used, with low mileage or high mileage.

So you don’t necessarily have to wait until your vehicle hits 75,000 to use high mileage oil. You’re just going to get much better performance from high mileage motor oil if your vehicle has high mileage.

Fortunately, you won’t experience any adverse reaction by using this type of oil in a vehicle with low miles.

Related: Is Driving With a Bad Oil Pressure Sensor a Good Idea?

5W20 vs 5W30 High Mileage

Now that you know what types of oil are available, let’s talk about the differences between 5W20 and 5W30. This will help you remember not to confuse these two very different oil types.

First, let’s break down what each number and letter means in an oil’s description. In 5W20, for example, the “W” stands for “winter,” while the “5” is the classification of the oil.

This lets you know well the oil will fare in colder temperatures. The larger number, in this case, 20, refers to how well the oil performs in hot temperatures.

You can tell the thickness of oil at any given temperature by examining these numbers. For thicker oil, you’ll want one with higher numbers.

With this information, we can determine that 5W30 is thicker compared to 5W20. When the oil has a thicker viscosity, it doesn’t flow as smoothly as thinner oil.

For cold-weather performance, you are better off using a thinner oil, whereas a thicker oil is recommended for warmer weather.

If your vehicle’s manufacturer recommends that you use 5W20, you should stick with that oil type. While both 5W20 and 5W30 motor oils are suitable for high mileage engines, the best viscosity type for your vehicle depends on how the manufacturer designed the engine.

Using 5W30 when it is advised that you use 5W20 can result in your vehicle not getting good fuel economy. Therefore, to ensure the best performance from your vehicle, continue using the same oil type as directed.

Related: Too Much Oil In The Car Engine – Signs & Solutions

What Is Viscosity?

This is how the flow of oil is measured, or any other fluid, for that matter. If a fluid has a low viscosity, it means it will flow easily. Low viscosity fluids are often referred to as being thin.

To give you an example of fluids with vastly different viscosities, consider water and molasses. Water has low viscosity, meaning it flows quickly and easily. Molasses, on the other hand, has high viscosity. Therefore, it flows slowly and not as easily.

Motor oil is somewhere in-between in terms of viscosity. You want to choose an oil type that flows the best given the temperature.

The key is to use oil that will adapt to the temperature and provide the best flow in your vehicle’s engine.

Can I Use 5W20 Instead of 5W30 in Lawn Mower?

When it comes to the smaller engines in lawnmowers, you’re better off using 5W30. However, this is only advised if your lawnmower has a 4-stroke engine.

This oil type provides the best protection in both hot and cold temperatures. Still, you need to check your lawn mower owner’s manual to be sure of the correct oil type.

If your lawnmower has a 2-stroke engine, it is imperative that you don’t use motor oil intended for a 4-stroke engine and vice versa.

Each oil type is vastly different from one another, and you could damage your engine if you use the wrong kind.

Four-stroke engines are the most widely-used engine in lawnmowers. That said, there are some lawnmowers that use 2-stroke engines. As such, you need to double-check your owner’s manual to ensure that you use the correct oil.

Two-stroke oil doesn’t have the thickness to withstand the performance needs of a 4-stroke engine. Using 2-stroke oil in a 4-stroke engine will cause permanent damage to your lawnmower.

Related: Is It Bad If Your Oil Smells Like Gas?

5W20 Temperature Range Chart

5W20 motor oil provides the best performance between the ranges of -22°F (-30°C) and 77°F (25°C).

For comparison, the temperature range of 5W30 motor oil is between -22°F (-30°C) and 95°F (35°C).

As you can see, there’s quite the difference in how these two types of oil perform. With these numbers in mind, it’s clear that using 5W30 motor oil instead of 5W20 could lead to serious damage to your engine.

Closest Oil to 5W-20

If you find yourself with a limited oil selection and there isn’t a 5W20 available, look for 0W20. Not only does 0W20 consist of a similar viscosity range, but it offers a very similar temperature range, as well (-31°F [-35°C] and 86°F [30°C]).

Is 5W20 Good for Summer?

As you have likely now concluded, 5W20 is better suited for colder temperatures. If you need motor oil for summertime performance, 5W30 is going to be the better bet. However, you should only switch to this oil type of your car manufacturer or personal mechanic recommend doing so.

You risk putting your engine in harm’s way by using an oil that your engine isn’t designed around. Remember, thinner motor oil (5W20) will flow through your engine better than 5W30.

During winter weather, stick with 5W20 unless directed otherwise. If there isn’t an issue with you switching to 5W30, use it during the summer months.

The Importance of Changing Your Oil on Time

All motor oil breaks down. When this happens, the oil loses its effectiveness and won’t provide optimal protection in your engine.

Motor oil serves a few essential purposes in your engine. For starters, it helps keep the moving parts in your engine lubricated and working properly.

Oil also serves to keep combustion byproducts clear of your engine’s cylinders and pistons. Doing so ensures the optimal performance of your vehicle.

It also works to catch dust and dirt entering your engine via the air intake system. The more you drive your vehicle, the higher the contamination level gets in your engine.

Thanks to the oil filter, most of these contaminants are collected. However, the protective additives in motor oil eventually get used up, resulting in the degradation of the oil.

At this juncture, the engine oil can no longer effectively do its job and needs to be changed. If you fail to change your oil regularly, you risk damaging your engine.

This is because there are too many contaminants entering your engine. Because there are so many factors that affect when oil should be changed, recommendations are provided from car manufacturers.

When your particular vehicle needs to have its oil changed depends on the make and model. Older vehicles should typically have their oil changed for frequently to avoid damage to the engine.

But it’s also wise to take into account things like how often you drive, the distance you usually travel in a day, typical driving conditions, and anything that affects the overall performance of your engine.

If more wear and tear is being put on your vehicle, it is generally a good idea to have your car serviced often. This will go a long way in prolonging the life of your vehicle.

If you decided to change your motor oil, here is a good website describing the procedure.


Knowing the correct oil to use in your vehicle will ensure optimal performance and reliability. If you are unsure which oil type to use, contact your car’s manufacturer or speak with a trusted mechanic.

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