20w40 vs 20w50 Engine Oil: Best Comparison Guide!

Every engine requires a certain viscosity grade of oil so that you can get the best performance and longevity. In order to get the best out of your motor oil, make sure you use the same grade as recommended by your manufacturer.

If it is a case where you are uncertain which oil is the most efficient one to use for your vehicle, we think it would be a good idea to check the owner’s manual this will inform you about the recommended viscosity grades and specifications.

20w40 vs 20w50 Engine Oil

20w40 vs 20w50 Engine Oil

What is 20w40?

20w40 engine oil is a multi-grade oil that is specially designed for optimal performance at various temperatures. It’s widely used in moderate-to-large diesel and gasoline engines, high-performance motorcycle bikes, as well as aviation vehicles.

We really appreciate the built-in cleansing feature of the 20w40 motor oil since it helps in terms of cleaning and controlling the build-up of sludge. It also plays a role in getting rid of the dirt deposits from the engine components, which helps to keep the engine fully functional.

With that said, we think that this oil is the perfect fit for off-highway industries. What this means is that vehicle that is operating within the construction, agriculture, and quarrying industries tend to prefer using this oil.

What is 20w50?

20w50 is a heavy-duty multigrade engine oil that is designed for high temperatures. It’s suitable for medium to large gasoline and diesel engines, aviation vehicles, as well as motorcycle bikes.

Race oil and high-temperature driving oils often use this oil due to its remarkable resistance to thinning. Unfortunately, some engine types find this type of oil too thick for use; if not used correctly, can cause serious damage to the vehicle’s engine over a period of time which can be costly.

It is best to keep in mind that when choosing an oil for your vehicle, the type you use depends on both the engine you have and the weather conditions in your area. Always adhere to the manufacturer’s recommended viscosity level – usually 10w40 or 20w50 – when making this decision.

Learn More: 15w40 vs 0w40 Engine Oil

What is the Difference Between 20w40 and 20w50?

The thing is that both 20w40 and 20w50 are known to be multigrade oils, classified according to their viscosity reading at operating temperatures.

It is safe to say that, these oils are primarily utilized in heavy off-highway vehicles such as construction and quarrying trucks. Additionally, they can be utilized by light to medium-duty trucks operating on highways.

What we love about multigrade oils is the fact that it is capable of withstanding various temperatures and keeping the oil’s flow at optimal levels, keeping your engine lubricated, clean, and running smoothly at all times. This ensures excellent engine performance over its lifespan.

Another advantage that comes with the 20w50 and 20w40 is their durability; they resist oil thickening caused by high-temperature driving, helping prevent your oil from leaking or becoming difficult to drain after long drives. This ensures your vehicle runs as you’d like it to every time.

There is no doubt that these oils are often sought-after for their ability to disperse dirt, thus decreasing the chance of rust. Not only does this extend your vehicle’s lifespan, but it can also lower operating and service expenses over time which is another bonus.

Read Also: 15W40 vs 20W50 Engine Oil

FAQs – Frequently Asked Questions

Q. 20w50 motor oil good for high mileage?

We don’t think that the 20w50 engine oil would make a great choice for a high-mileage engine since it wasn’t designed for that purpose. However, it tends to work well for older vehicles, while on the other hand, 20w40 helps reduce wear-and-tear on your engine, decreasing the possibility of costly repairs or replacements in the future.

Q. Is 20w50 motor oil good for bikes?

If your motorcycle or the classic car runs in hot climates, 20w50 is recommended. This oil is slightly thicker than 20w40 and can better lubricate the crankshaft and other engine components. However, we strongly believe that it is best to follow your owner’s manual’s recommendations when using oil in your engine since not all engines respond equally well to different viscosity grades.


When it comes to choosing the best viscosity oil for your engine, we think the first thing you should do is read your owner’s manual. Your owner’s manual will definitely be able to guide you on the right path so that you can make the best decision possible. We don’t think it would be a good idea to decide on your own especially if you’re a newbie.