What’s The Best Oil for Harley 103 [Buying Guide 2021]

Whenever we talk about resilience and strength in engines, motorcycle engines are what comes to our minds.

They are capable of withstanding extreme temperatures and intense pressure for long hours without a hitch.

But do you know what powers them to do it? It is the engine oil and here we are talking about the best oil for Harley 103 engine.

The only way your engine will run as smoothly as possible if it has been fueled with high-quality mobile oil.

Best Oil for Harley 103

Your engine oil is capable of making or breaking your riding experience which is why when it comes to choosing the right oil, we suggest you read through a detailed buyer’s guide so you don’t end up making a mistake.

Since there are hundreds of options available in the market, we have narrowed down some of the best oil for Harley Davidson 103 down below.

Take a look at them and see if anything suits your requirements.

Comparing 7 Best Oil for Harley 103

Motorcycle OilLiquid VolumeLasts up to
Red Line 902267 Quartz10,000 miles Check Price
Castrol 159AE132 Fluid Ounces8,000 miles Check Price
Mobil 1 9693632 Fluid Ounces12,000 miles Check Price
Royal Purple 36250-6PK1 Quart9,000 miles Check Price
Lucas Oil 107006 Quartz6500 miles Check Price
Maxima VTTOCK21192 Fluid Ounces9,000 miles Check Price
Klotz Oil32 Fluid Ounces10,000 miles Check Price

1. RedLine 20W50 Racing Oil 90226

Redline 20w50 Racing Oil

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The very first engine oil that we would like you to look into is the RedLine 20W50 motorcycle oil, an oil that was exclusively designed for sports bikes and motocross.

The oil is popular for working in high temperatures and it reduces oil thinning which is a consequence of extreme conditions.

Another aspect that we were thrilled about with regards to this oil was the fact that it comes with one-of-a-kind, anti-wear, and tear properties that improve the lifespan of the engine itself.

With this mobile oil in your motorcycle, your engine itself is going to remain in safe hands and last longer than usual.

Ideal for heavy engines

The Red Line V-Twin oil is an ideal oil for heavy engines including sportbikes. The oil has anti-wear properties and also enhances the overall lifespan of the engine.

It is going to keep your engines protected and ensure the performance isn’t compromised under drastic weather conditions.

Extended drain intervals

Even though this is costly engine oil, the fact that it allows the user to enjoy longer drain intervals makes it pretty much cost-effective.

The Red Line 20W50 oil can last up to 10,000 miles and allows the rider to cover long distances efficiently.

The oil has proven to be an efficient source of power for heavy engines and works great for Harley 103.

It doesn’t thin in extreme temperatures which is why it is recommended for extreme use.

Great bottle design

Don’t like using a funnel when pouring oil into your engine?

Well, the RedLine powerpack oil comes with an efficient bottle design that is going to make filling your engine a whole lot easier.

It features a very narrow mouth and has been shaped like a flask that keeps the oil from spilling.

With this, you will be able to fill your engine directly from the bottle and not make a mess at all.

Final verdict:

The RedLine 20W50 motorcycle oil is a highly efficient and powerful engine oil that is highly recommended for heavy engines.

It can last up to 10,000 miles, doesn’t get thin under extreme temperatures, and works great for covering long distances.

  • Powerful engine oil
  • Lesser drain intervals
  • Efficient bottle design
  • Great for heavier engines
  • Higher price point

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2. Castrol Motorcycle Oil 20W50 159AE1

Castrol Motorcycle Oil 20w50

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The second engine oil that we recommend for Harley 103 is the Castrol motorcycle oil 159SE1.

There are a number of reasons why suggest using this motorcycle oil, the top of them being Castrol is a reliable company, one that we fully and utterly trust.

Of course, over years, Castrol has shown some weaknesses over the years but they always came through in the end.

When we read through the properties of Castrol 159AE1 oil, we had a gut feeling that it would perform well and won’t disappoint us in low temperatures.

And we were proven right. For people who live in cold weathers or for someone who is looking for an engine oil exclusively for winters then this 20W engine oil is what you can rely on.

Better engine acceleration

The very first thing that we were impressed with when it came to this engine oil is how much it improved the engine performance.

It enhances the overall acceleration time with efficacy and allows you to drive smoothly and conveniently even in lower temperatures.

Lesser oil change intervals

Another benefit of using this engine oil is that there will be lesser oil change intervals.

In our experience, it can last up to 8,000 miles before you will have to change it.

By using the Castrol V-Twin oil, your clutch is never going to slip, and neither your motorcycle engine is going to spike up when used intensively.

Certified engine oil

Last but not least, the Castrol motorcycle oil uses the brand’s signature technology known as Trizone.

This is certified engine oil and complies with the standards set by API and JASO MA2.

JASO and API standards are set by the oil industries as benchmarks to ensure the quality of oils being used by the automotive manufacturers.

Final verdict:

Castrol oil is top-shelf engine oil that has proven its worth over time.

It lasts up to 8,000 miles, lowers your oil drain time period while enhancing the performance and speed of your engine even in the lowest temperatures.

  • Features signature Trizone technology
  • Great quality and great performance
  • Very feasible
  • Smooth engine running
  • Packaging isn’t good enough
  • Excessive oil burn off

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3. Mobil 1 20W50 Full Synthetic Motorcycle Oil

Mobil 1 20W50 Motorcycle Oil

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Searching for an ideal oil for Harley 103? Well, we are sure it will end with the Mobil 1 20W50 synthetic oil.

The oil can be used in both ways, when engine and transmission are separate or when they are common.

We absolutely loved this engine oil because it accelerates the engine performance of your motorcycle and ensures a smooth drive.

Now your clutch is never going to miss because this oil will connect it with the engine in a single kick.


The reason why this engine oil ended up on our list is that it can withstand harsh driving conditions and even proves to be worthy enough under lower temperatures.

It has various long-lasting properties and reduces the number of times you have to replace your oil in a month.

It can last up to 12,000 miles and delivers efficient driving performance. We also recommend the use of this oil for covering long-distances.

Fuel-saving properties

Although, this oil is an expensive engine oil what makes it one of the best is the fact that it helps you save a lot of fuel.

With this oil, you will enjoy long draining intervals and great fuel efficiency, something that we do not get with our regular oils.

It is also highly recommended for people who have a knack for covering long distances on their motorcycles.

If you like to improve the speed and performance of your bike, then you should absolutely go for this one.


Even though the price of this engine oil is pretty high, yet we consider it to be a cost-effective oil that you can use.

The Mobil 1 20W50 V-Twin oil holds stellar ratings on Amazon and is said to be one of the best engine oils available in the market for Harley 103.

One gallon of this oil and be prepared to watch your motorcycle go zoom with speed and high-grade performance.

Final verdict:

The Mobil 1 synthetic motorcycle oil is cost-efficient and incredibly powerful engine oil that will accelerate the speed and performance of your motorcycle to a whole new level.

It has long draining intervals and provides absolute convenience to avid travelers. You can also use this oil for your Softail Deluxe.

  • Cost efficient
  • Very powerful
  • Longer draining intervals
  • Enhanced engine performance
  • Little expensive for some users

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4. Royal Purple HPS 20W50 Synthetic Oil

Royal Purple 20W50 Synthetic Oil

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Royal Purple is one of the most popular brands for buying summer oil for Harley 103.

The brand has offered high-performance and incredible synthetic Mobil oils that enhance the overall performance of the engine while keeping it protected in the long run.

Just like most of the traditional oils, the Royal Purple HPS oil isn’t made out of crude oil and works for both, hot and cold temperatures.

The viscosity rating, one of the most important aspects of buying engine oil is 20watts in colder conditions and 50 in high and average temperatures.

Also, before you purchase an engine oil, make sure you have checked your vehicle’s manual so you buy the right oil with the correct weightage.

The Royal Purple 36250-6PK is an expensive engine oil but it does have its perks that cannot be denied.

Excellent performance

What is the one thing we look for when purchasing the best oil for Harley Davidson 103?

Well, we need our motorcycles to perform with excellence which they surely will if you have Royal Purple synthetic motor oil in your grasp.

The oil escalates gas mileage quite a notch and enhances the mechanical performance of your motorcycle.

The oil is exclusively designed for heavy-duty engines so their performance can be boosted and they run smoothly off and on roads.

Exclusive formulation

This oil isn’t like your regular engine oils. The brand has crafted it with an increased presence of Zinc as the anti-wear agent, making it a unique blend.

This mineral provides protection to your engine against corrosion and ensures it can withstand increased viscosity and higher temperatures.

The oil also enhanced the seal between the cylinder wall and piston ring to improve the bike’s horsepower for a better and smooth riding experience.

Better fuel efficiency

Another added benefit of using the Royal Purple motor oil is that you will not have to worry about frequent oil changes.

The oxidation stability will allow you to drive without needing to change the oil too often.

You will not only be saving your environment from the adverse effects of oil changing but will also save a lot of time and money in the process.

Final verdict:

The Royal Purple synthetic oil is expensive but very cost-efficient engine oil that improves the performance of heavy-duty engines and is meant to last for a long time.

It also improves the lifespan of your Harley engine and keeps it protected from foreign pressure.

  • Reduces noise
  • Better mileage assurance
  • Works for sports and regular bikes
  • Protects your engine
  • Leakage in bottle
  • Blows up the bearing
  • Customer service needs improvement

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5. Lucas High-Performance Motorcycle Oil

Lucas 20W50 Motorcycle Oil

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If you have used every top oil available in the market to get a smooth performance out of your motorcycle and still no success, then why don’t you consider the Lucas high-performance oil.

Though Lucas oil is a very under-rated engine oil brand in the market if you have gone through their Amazon marketplace, then you will know the stellar rating brand holds on the web.

Their engine oils are very powerful and provide added strength to your bikes.

Not to mention, they also lessen the drain intervals which is a big deal when it comes to changing engine oils.

The Lucas 20W50 synthetic motorcycle oil is an affordably priced mobile oil that is going to keep your engine protected and ensure you have a smooth riding experience at all times.

Lesser draining intervals

With this oil, you will not have to change your engine oil too often. The oil can last up to 6500 miles and provide optimal riding performance.

We also loved the fact that before, we couldn’t rely on our motorcycles for covering longer journeys but after using the Lucas engine oil, we could because the engine never gave upon us.

Smooth riding

Oftentimes, people feel their engines heating up when they are going off-road. This is a common thing to experience with low-quality engine oils.

The Lucas oil 10700 reduces the thinning of oil in extreme temperatures and keeps your speed consistent.

You will also not have to worry about running out of power or missing your clutch. The oil is powerful enough to get your bike started in a single kick.

Quieter performance

Last but not least, the Lucas high-performance oil delivers a very powerful yet quiet engine performance.

This is unlike something we have ever experienced before. Our engine ran really quiet and extremely smooth.

The mobile oil also features a cleaning detergent that keeps your engine well-protected for a very long time.

Final verdict:

The Lucas motorcycle oil is an incredible choice given how affordable the mobile oil truly is.

It is meant to last for a very long time, improves the performance of your engine, and keeps your motorcycle parts well-protected.

  • Impressive performance
  • No thinning
  • Quieter engine
  • Smooth running
  • A little expensive for some riders

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6. Maxima Synthetic Oil For Harley Davidson

Maxima Oil For Harley

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Every rider is in search of an engine oil he can truly depend on, one that will take off his engine and all the other parts of his motorcycle.

So when choosing a mobile oil, you need to opt for something that not only delivers smooth riding performance but also extends the lifespan of your engine.

The Maxima engine oil has been produced out of minerals it exclusively focuses on 6, 5, and 4-speed gears to ensure your engine kick starts in just one go.

It is the perfect oil for your Harley 103 not to mention, the oil comes at a very reasonable price point.

Exclusive formulation

The reason why Maxima synthetic oil has become so popular among Harley 103 users is because of its efficient formulation.

It comes with a very unique and robust formula that makes it the perfect oil for heavy engines.

The mobile oil has mineral properties that allow it to provide protection against wear, tear and shock loads if the viscosity is lost.

Because of its incredible additives, the oil ensures that you have access to a smooth-shifting process even under extreme RPM.

Great for extreme situations

Since the Maxima VTTOCK21 oil features mineral-grade quality, it will ensure you are able to acquire a very smooth and optimal riding experience.

It features clean detergents that keep the engine from getting damaged by corrosion and protect your vehicle and its parts effectively.

Great for covering long distances

If you have always been afraid of taking your motorcycle on a long-distance adventure, worry no more.

The Maxima oil is a powerful mobile oil that lessens the drain intervals and can last up to 9,000 miles.

With this oil in your motorcycle, you will never have to worry about your motorcycle giving up on you in the middle of your journey.

Just make sure you keep a thorough check whenever drainage is due and maintain your motorcycle regularly.

Final verdict:

The Maxima synthetic oil is an affordable alternative to high-end engine oils that are too expensive to put your money on.

This mobile oil is a great pick for Harley 103, provides optimal performance, and enhances the lifespan of your engine along with other parts of your motorcycle.

  • Great alternative for high-end engine oils
  • Reasonably priced
  • Great choice for Harley 103
  • Protects engine from wear and tear
  • Oil transmission isn’t as heavy as it should be

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7. Klotz V-Twin Full Synthetic Oil Change Kit

Klotz Oil

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The last engine oil that we want you to consider is the Klotz oil. It is specifically designed to meet all the needs of a motorcycle and an ATV engine.

We have to say that this is a very special oil that has taken years to develop after a lot of research and experiment.

The biggest benefit of using the Klotz V-Twin oil is that it stabilizes the viscosity.

The regular engine oils cause great oil consumption and can break off oil in the middle of your journey.

This is why this oil will help you save a lot of your money and show great resistance against intense temperatures while maintaining its purest form.

Ensures smooth performance

One of the most common issues faced by motorbike riders is when they have to endure bumpy rides because there is debris in their engine oil.

This is a very common phenomenon, one that can be easily avoided by using high-quality and mineral engine oil.

The Klotz oil prevents debris and metal in the oil while delivering a very smooth riding experience.

Works well for transmission and engines

If you happen to own a bike that is in need of an oil that will work well for transmission and engine both then Klotz has got you covered.

It is capable of running a light-duty motor with great efficiency and is going to be the ideal choice for your water-cooled engine.

The oil is a high-quality product from a promising brand and it improves your gas mileage.

No noise

Last but not least, we all want our bikes to run smoothly, without making more noise than they have to.

The Klotz oil is capable of shutting down extra noise and delivers an optimal riding experience. Also, the oil will reduce the oil change intervals and it can last up to 10,000 miles.

Final verdict:

The Klotz oil is an incredible engine oil for Harley 103. It delivers optimal performance and promises great speed and viscosity.

The brand also offers great customer service and you can get support any time you need.

  • Improves speed
  • Stabilizes viscosity
  • No noise
  • Smooth clutch shift
  • Not recommended for heavy duty engines

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Buyer’s Guide:

Oil for Harley 103 Buying Guide

Before you make the final choice for the best oil for Harley 103, here is some more information that we would like you to unfold.

You need to take some facts and aspects into consideration before you choose an engine oil.

Just because an engine oil on the web has received high-ratings doesn’t mean it will be the perfect fit for your motorcycle.

There are some points you need to keep in perspective and we are enlisting all of them below for you to have an understanding.

Type of Motor Oil:

The very first thing that you need to keep in mind when choosing an engine oil is the type of oil you need. There are three main types of engine oils available that you can choose from.

Mineral OilSynthetic OilSemi-synthetic Oil
Refined crude oil is known as mineral oil. It doesn’t really provide a lot of stability with regards to viscosity and may not suit heavy-duty engines. It will also not work for higher and intense temperatures.
Synthetic oil or full synthetic oil is made out of various compounds. It delivers a great level of stability and is capable of working in extreme temperatures with great results.
Semi-synthetic oil is a combination of crude and synthetic oil. It is capable of doing the job well and doesn’t come at higher price points. It is an ideal choice for high-speed motorcycles.

Nobody in the world would want to opt for engine oil that isn’t meant for their vehicle. When choosing an oil, this is the most important factor that you need to consider.


When we refer to longevity with regards to oil, it means that for how long an oil tank can run before you have to refill it.

You must have noticed that high quality comes at a steep price. The oils that have better longevity can be costly.

However, when it comes to motorcycles, we all know that they are an extremely important asset of yours, one that you would want to take the best care of.

We suggest that instead of buying cheap oils, you buy oils that have better longevity.

They will not only protect your engine and other parts of your vehicle but will also help you save money.

Easy to clean

The cleanliness of your motorcycle largely determines its performance.

There is a great deal of debris and metal that gets stuck inside your engine oil on a daily basis, so much so that you won’t be able to imagine.

You obviously cannot see from outside whether your engine oil is clean enough or not.

So you will have to change the engine oil frequently which isn’t an easy task and can take a lot of time.

However, there are some high-quality engine oils available in the market that come with self-cleaning features.

These kinds of oil keep your engine clean and ensure you have a smooth, less bumpy riding experience.


You can compare engine oil with your blood. If you have an O+ blood group, you obviously cannot get injected with another blood group type.

Before you purchase an engine oil, always check the type of engine oil that is compatible with your bike.

Some engines will only work with traditional oils only while some can work with synthetic and semi-synthetic oil.

You will always find an instruction manual when you purchase your bike. Always keep it safe and check the mentioned engine oil before buying one.

If you end up refilling your engine with the wrong mobile oil then it would probably leak up at some point.


There is a reason why online reviews exist. They are a new source to get information regarding the product you plan on purchasing. Always make use of them as wisely as you can.

Before buying engine oil, you can always check out its review section and get more certainty about your purchase.

This way, you can always get an opinion from someone who has already used the engine oil you plan on buying and never regret your decision.

Frequently Asked Questions:

When and how often should I change my engine oil?

The oil change greatly depends on the owner’s manual. Most commonly, complete oil drainage should be performed at 5,000 miles. However, some latest engine oils can last up to 10,000 miles.

Which oil is better, synthetic or standard?

Synthetic oils have better longevity whereas standard oils require frequent oil change. Keeping in mind what kind of an engine you own, you can always go for either but synthetic oil promises better performance.

Should I not use synthetic oils at some points?

No, synthetic oils can always be used anytime you want.


So, this is everything we had on the best oil for Harley 103.

As you can see, depending on the kind of vehicle you own and its compatibility with engine oil, you can choose either a traditional, synthetic, or semi-synthetic oil.

Synthetic oils are the most promising engine oils available that offer phenomenal longevity, better performance, and prevent the engine from sustaining damages.

If there is anything you would like to add here or any suggestions you may have in this regard, do let us know through your feedback below.

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