Harley Davidson Twin Cam engines are pretty great. They’re easily upgradable, sound incredible, and are very reliable if maintained properly.
One of the most important things you can do to keep your Twin Cam running smoothly is to use the best oil possible. These engines do get pretty hot, especially if you’ve got a big bore kit with aggressive cams, so you need engine oil that can handle the heat.
In this article, we’ll take a look at the best engine oils for Harley Davidson Twin Cam engines, both stock and modified. We’ll also give you a few money-saving tips so you can keep your Twin Cam running great without breaking the bank.
Also Read: Motorcycle Oil Change Cost & Money Saving Tips
The 5 Best Engine Oils for Harley Davidson Twin Cam
 | Best Overall 1. Mobil 1 V-Twin Advanced Full Synthetic 20W-50 |
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 | Best Value 2. Lucas 20W-50 Synthetic |
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 | Premium Pick 3. Royal Purple Max-Cycle 20W-50 Synthetic |
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 | Lowest Price 4. Liqui Moly Street 20W-50 Conventional |
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 | Winter Protection 5. Castrol Actevo 20W-50 Part Synthetic |
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1. Mobil 1 V-Twin Advanced Full Synthetic 20W-50
This is one of the best motorcycle oils on the market, period. It’s fully synthetic, so it can definitely handle the heat and stress of a Stage 4 Twin Cam engine.
It’s designed to be used in “all three holes” – engine, transmission, and primary. So if you’re looking for an oil that can do it all, this is a great option.
It also has an additive package that’s specifically designed for V-Twin engines, including an impressive zinc content of 1750 PPM, so you know it’s going to do an outstanding job at protecting your engine.
Furthermore, it meets and exceeds the requirements of API SH, SG/CF, and CD, which are one the toughest in the motorcycle industry.
Now, the V-Twin Advanced 20W-50 is on the expensive side, but it’s definitely worth the money – especially considering the zinc content. If you want the best possible protection for your engine, especially on hot summer days – this is the oil to get and it’s definitely our favorite.
2. Lucas 20W-50 Synthetic
This is another great fully synthetic option that’s really popular with Twin Cam owners and even racers.
The main selling point of the Lucas 20W-50 is that this oil will reduce leaks, reduce noise, reduce temperature, and increase engine life. And with a healthy Zinc content of 1058 PPM, it definitely seems to be true.
It’s also a great choice for modified engines, as it can handle the extra stress and heat that they produce – that’s one of the reasons why guys with higher compression Twin Cam 88 love this oil.
Furthermore, this oil also meets and exceeds the requirements of JASO MA & JASO MA-2 (low ash), so you know it’s good stuff.
There are really not many downsides to this oil. It’s got a decent amount of zinc and is perfect for primary, transmission, and the engine. It’s definitely one of the best oils for Harley Davidson Twin Cam on the market and it’s also very affordable – especially considering that it’s fully synthetic.
3. Royal Purple Max-Cycle 20W-50 Synthetic
The Royal Purple Max-Cycle 20W-50 is another great fully synthetic option for Harley Davidson Twin Cam engines.
Did you know that around 60% of engine wear occurs at startup? Royal Purple certainly knows that and has included the Synarlec additive package, which does a great job at improving wear protection at startup.
The Max-Cycle 20W-50 also has an impressive zinc content of 1200 PPM, so you know it’s going to do a great job at protecting your engine. Furthermore, its full synthetic base oils can withstand the extreme heat and stress of high-performance engines, which is perfect for big bore kits and modified Twin Cam engines.
This oil also meets and exceeds the requirements of JASO MA2, which is the highest wet clutch compatibility rating in the motorcycle industry and can be in all primary, transmission, and engine.
So if you’re looking for an oil that will protect your engine and reduce wear, especially at startup – the Royal Purple Max-Cycle 20W-50 is a great choice.
4. Liqui Moly Street 20W-50 Conventional
If you’re not into synthetic oil or you just want to save a little bit of money, the Liqui Moly Street 20W-50 is a great option.
It’s a conventional oil that meets all of the strictest requirements for Harley Davidson Twin Cam engines, including the latest JASO MA2 standard. Because of that, it works well with catalytic converters and improves wet clutch performance.
It also has excellent anti-wear and anti-corrosion properties, which will help to extend the life of your engine.
The Liqui Moly Street 20W-50 is a great choice for those who want a high-quality conventional oil that will do a great job at protecting their engine.
5. Castrol Actevo 20W-50 Part Synthetic
The Castrol Actevo 20W-50 is a great option for those who want the best of both worlds – a partially synthetic oil that’s affordable and does a great job at protecting your engine.
The Castrol Actevo 20W-50 is a part synthetic oil that contains an additive package (Actibond) that clings to engine components for longer, which reduces oxidation and wear during startup.
It also provides excellent protection against corrosion, deposits, and sludge build-up – even under the most extreme conditions. The Actevo 20W-50 exceeds the API-SL and JASO MA2 requirements and can be used in primary, transmission, and engine.
The Castrol Actevo 20W-50 is a great choice for those who want an affordable oil that will provide extra protection from corrosion during the cold winter months when your Twin Cam is not being used as much.
How to Buy the Best Oil for Harley Davidson Twin Cam
Now that you know a little bit more about the best oils for Harley Davidson Twin Cam engines, it’s time to make a decision on which one is right for you.
Weight (Viscosity) Rating
The single most important thing to look for when buying oil for your Harley Davidson Twin Cam is the weight or viscosity rating.
Engine oil viscosity is measured by its thickness, or how easily it flows. The thicker the oil, the higher the viscosity rating.
Now, the thickness of engine oil changes with temperature – that’s why you’ll often see two numbers on engine oil containers, like 10W-40.
The first number (10W) is the oil’s viscosity when it’s cold, and the second number (40) is its viscosity when it’s hot.
You want to make sure that you choose an oil with the correct viscosity rating for your Harley Davidson Twin Cam. If you use too thin of oil, it will not provide enough protection for your engine and if you use too thick of oil, it can cause oil starvation.
Harley Davidson recommends using a 20W-50 oil in all of their Twin Cam engines. This oil is thick enough to provide adequate protection for your engine, but not so thick that it will cause oil starvation. You can and should go lower to 10W-50 if you’re planning on starting your engine in temperatures below 50° F.
If you live in a warm climate and you’re only going to be using your Twin Cam during the summer months, then 20W-50 should be your go-to – that’s what these engines like best.
Conventional VS Synthetic VS Part-Synthetic
The next thing you need to decide is whether you want to use conventional oil, synthetic oil, or part-synthetic oil in your Harley Davidson Twin Cam.
Conventional oil is the least expensive option and it does a good job at protecting your engine, but it doesn’t do as good of a job as synthetic or part-synthetic oil.
Synthetic oil is more expensive than conventional oil, but it has been proven to be better. This is because synthetic oil is designed to flow better and withstand higher temperatures without breaking down, which is extremely important for the air-cooled Twin Cam that gets really hot.
Part-synthetic oil is a blend of conventional and synthetic oil. As you can imagine, part-synthetic engine oil provides a lot of the benefits of synthetic oil, but costs considerably less.
If you’re looking for the best of both worlds – an oil that’s affordable and does a great job at protecting your engine – then the Castrol Actevo 20W-50 is a great choice.
Price
The last thing you need to consider when choosing the best oil for your Harley Davidson Twin Cam is price.
While it’s important to find an oil that’s affordable, you also want to make sure that you’re not sacrificing quality for price.
The best way to strike a balance between quality and price is to buy in bulk. You can often find good deals on oil when you buy it in larger quantities. A Twin Cam will last forever if taken care of properly, so chances are, you will need lots of engine oil in the future anyway.
How Often Should You Change the Oil on a Twin Cam?
Harley Davidson recommends changing the oil in a Twin Cam every 4,000 – 5,000 miles. This is a good rule of thumb to follow, but you may need to change your oil more frequently if you ride in dusty or dirty conditions, or if you let your Twin Cam idle for long periods of time.
If you live in a really cold climate, you may also want to change your oil more frequently. In cold weather, moisture starts to condense and develop inside the engine and the oil tank.
In freezing temperatures, this moisture can freeze and actually block the oil lines, which would cause oil starvation. If the moisture doesn’t freeze, then it will get mixed up with engine oil and make the oil into a thick sludge – this is bad for your engine.
In order to prevent those scenarios, Harley Davidson recommends changing the oil more frequently during cold winter months.
How Often Should You Change the Primary Oil on a Twin Cam?
You should change the primary oil on your Twin Cam every 10,000 miles, but if you want your primary to last longer, then we recommend changing the oil with every engine oil change.
Changing your primary oil every 4,000 – 5,000 miles will help to prolong the life of your primary and keep it running smoothly.
Can You Use the Same Oil in the Engine, Transmission, and Primary?
You can use the same oil in the engine, transmission, and primary, but we recommend using different oils for each.
The best oil for the engine is a 20W-50, the best oil for the transmission is a 75W-140, and the best oil for the primary is a 20W-50.
Can You Mix Different Brands of Oil?
You can mix different brands of oil, but we don’t recommend it.
If you do mix different brands of oil, make sure that they have the same viscosity. For example, you can mix a 20W-50 with another 20W-50, but you shouldn’t mix a 20W-50 with a 75W-140.
The best way to avoid any problems is to just use one brand of oil.
Final Thoughts
Choosing the best oil for your Harley Davidson Twin Cam is important if you want your engine to last a long time.
There are a lot of different oils on the market, but we recommend either synthetic or part-synthetic oil.
In either case, make sure that you get the right viscosity oil for your temperature range, and that you change the oil every 4,000 – 5,000 miles (or more frequently if you ride in dusty or dirty conditions).
We also recommend changing the primary oil every 10,000 miles.
If you follow these guidelines, then you should have no problem keeping your Twin Cam running smooth for a long time.
Jake is the site’s primary contributor.
Motorcycles and automotive repair have been a big part of his family for generations, therefore it’s only natural that he decided to become a heavy-duty diesel tech.
Outside of work, you’ll find Jake restoring and riding rare street bikes and ATVs.