5w30 vs 5w40 – Which is Best For Your Motorbike?

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Your motorcycle’s engine performance and lifespan is directly influenced by the lubrication system. That is the reason you might be wondering which oil viscosity would work best for your two-wheeler.

Also Read: 10w40 vs 5w40 – What is the Difference?

That said, the choice of your engine oil will determine your motorbike protection before wintertime. Below is a review of the top two most popular types of engine oil on the market: 5W30 and 5W40 motor oil.

Engine Oil Explained – What the Marking and Numerals Mean?

The engine oil intended for cold weather conditions must retain its fluidity for cold engine lubrication.

To achieve this feat, different types of motor oil have different markings and numerals to distinguish them. These markings help you choose the right oil for a particular region or season.

Take an example of 5W30 engine oil. The digit that comes before the letter “W” is the temperature in degrees celsius which the oil pump can operate efficiently.

This particular temperature allows the crankshaft to turn faultlessly with a torque strong enough to start the engine.

The letter “W” stands for winter or the point at which you can use the lubricant in extreme cold weather conditions.

The digits that follow the letter indicate the high-temperature characteristics that are defined by lower and upper thresholds of the viscosity (kinematic) at 100 degrees Celsius.

This value also includes the dynamic victory at 150 degrees Celsius with a shear rate of 106 s-1.

Most manufacturers use different additives in engine oils to create universal products that can withstand a wide temperature range. Each additive helps in reducing the over-dependence of motor oil viscosity on temperature.

5W30 Engine Oil

The 5W30 is one of the most preferred engine oils by many people for various reasons. To begin with, this oil works well with many models of motorbikes including vehicles with different engine models. Second, it covers a wide range of temperatures although it is ideal for warmer places. Regardless of all these reasons, the oil performs well on many vehicles and at different temperatures.

5W40 Engine Oil

Even though 5W40 engine oil is not as common as the 5W30, it has several outstanding features. These features optimize the performance of your motorcycle engine not to mention its lifespan. They include:

  1. Protecting the motorbike engine against deposit and dirt buildup as well as damage
  2. Making sure that the engine starts up quickly even in colder environments. This also includes the efficient circulation of oil in freezing temperatures
  3. Accessing all moving parts in the engine fast

Although the 5W40 behaves like five-rated single-grade engine oil in winter conditions, it doesn’t become thinner than the 40-rated single-grade engine oil when the temperature is high.

5W30 and 5W40 Comparison

Most people prefer the 5W30 over the 5W40 for a simple reason. The 5W30 engine oil provides a smooth flow to the oil pump. In addition, it is more suitable when it comes to flow through the engine at a higher temperature.

But both engine oils work pretty well and they provide faster lubrication to every movable engine part.

Since these engine oils have the same viscosity ( denoted by number 5), their performance will remain the same under normal conditions.

The only major difference between them is that the 5W30 oil has a lower viscosity while the 5W40 has a higher viscosity when the motorbike engine is operating at a higher temperature.

5W30 and 5W40 – Engine Oil Characteristics

The two types of engine oils share similar characteristics. They both maintain viscosity optimal at -30 degrees Celsius for engine start. Their fluidity stands at -35 degrees Celsius.

However, each motor oil’s high-temperature characteristics differ from each other.

The 5W30 has a kinematic viscosity variation range of 9.3 to 12.5mm2 per second. Its dynamic viscosity stands at 2.9 mPas. When it comes to 5W40, the situation is somehow different.

In this case, the kinematic velocity is 12.5 to 16.3 mm2 per second but the dynamic viscosity is 3.5 mPas.

These products have their own advantages and disadvantages that you should know before choosing any of them.

For example, the 5W40 engine oil creates a thicker oil film that is stronger and excellent at sealing gaps. This makes it a perfect choice for significant loads as well as high-performance sports cars.

Its downside is seen in high cranking resistance which can interfere with the motor dynamics. Apart from that, its wider lubricant temperature range gives it a shorter lifespan.

The positive side of using the 5W30 motor oil comes in its higher pumpability in the lubrication system. This engine oil can clean all power unit parts of the motorcycle more effectively.

As a result, it contributes to the cooling of unit parts while promoting fuel economy. But an increase in gaps due to friction can lead to leaks when you use this type of engine oil.

5W30 or 5W40 Engine Oil – Which Should You Choose?

Your choice of engine oil will depend on a number of factors. Some of these factors may include how often you use your motorcycle, where you ride it and at what speed.

If you are always getting in any of the mentioned incidents, you should consider buying engine oil that has 5W40 viscosity. If you choose to be eco-friendly, practice calm driving and fuel economy, then 5W30 motor oil should be your first choice.

Besides viscosity, you must take into account the following parameters when purchasing motor oil for your motorcycle:

  • Composition of the motor oil base. In this regard, you should choose between mineral oils and synthetic oils.
  • Consider ACEA and API classification. These classification systems will help you determine the amount of ash, additive content and other parameters in a particular oil.

Check with your motorcycle’s manufacturer to know if it is possible to replace the 5W30 engine oil with 5W40 oil or vice versa. If you don’t follow this directive, you may cause your motorbike’s engine to break down prematurely.

Final Verdict

At this point, you must know which oil engine between the 5W30 and 5W40 is right for your motorcycle. In this case, you can go for the 5W30 if you are intending to enjoy calm rides.

But if you are looking forward to riding your bike at top speeds, then the 5W40 will work best for you. Otherwise, both engine oils provide excellent results without damaging engine parts.

Josh Berry - MotoShark Editor
Josh Berry
I'm a off-road enthusiast, extreme sport fan and the editor of MotoShark. If you have any questions or suggestions regarding this article, please leave a comment or contact me.

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