What Kind of Oil Should I Use in my Harley Davidson?

The majority of Harley Davidson motorcycles utilize a separate sump for each lubricant, meaning there is one sump for the engine, one sump for the transmission, and another sump for the primary chaincase. This scenario might be a little confusing for Harley owners in that they may ask “should I use the same oil in all three sumps of the bike, or would it be better to utilize a lubricant specifically formulated for each sump area?” Let’s delve into these three areas and decide the answer to the question “what kind of oil should I use in my Harley Davidson?”

In this blog post, we’ll focus on the leader in synthetic lubricants, AMSOIL. AMSOIL offers a complete line of lubricants specifically engineered for V-Twin motorcycles and for Harley’s. In fact, some AMSOIL employees own Harley Davidson motorcycles and position AMSOIL as a synthetic oil manufacturer that can offer some interesting insights and recommendations concerning the use of their synthetic V-Twin motorcycle lubricants.

What Kind of Oil Should I Use in my Harley Davidson bike? Use AMSOIL!

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In terms of the question “what kind of oil should I use in my Harley Davidson?” AMSOIL recommends AMSOIL 20W-50 Synthetic V-Twin Motorcycle Oil for the engine, primary chaincase, and transmission on the majority of Harley’s (please consult AMSOIL’s Motorcycle Product Guide for specific recommendations.) By utilizing a singular lubricant such as AMSOIL 20W-50 Synthetic V-Twin Motorcycle Oil for all three sumps, you benefit from convenience. This will reduce your costs and will translate into fewer half-used bottles of oil lying around your garage.

By using just one oil, you gain simplicity. It is a lot easier to remember one lubricant than trying to remember three. Most importantly, this specifically engineered synthetic lubricant delivers fantastic all-around performance for all three areas of your bike. AMSOIL engineered its 20W-50 Synthetic V-Twin Motorcycle Oil to be a superior all-around synthetic oil. It provides excellent engine protection because of its ability to combat wear, maintain cleanliness, reduce heat, and minimize and prevent corrosion during storage.

AMSOIL 20W-50 Synthetic V-Twin Motorcycle Oil.
AMSOIL 20W-50 Synthetic V-Twin Motorcycle Oil

Synthetic V-Twin Motorcycle Oil was formulated to meet GASO MA/MA2 standards. It offers outstanding performance in the primary case because of its wet clutch compatibility. Clutch plates are able to engage and disengage without slipping or loading for smooth shifts because its frictional properties have been dialed into the clutch plates.

Another reason Synthetic V-Twin Motorcycle Oil is an excellent all-around singular lubricant to consider for Harley’s is that it was engineered with a shear-stable formulation. Even in the presence of intense pressure and the churning action of high RPM transmission gears, it resists viscosity loss, thus providing reliable and superior transmission protection.

These are all compelling benefits to utilizing AMSOIL 20W-50 Synthetic V-Twin Motorcycle Oil as a singular lubricant for the three separate sumps. With that said, some motorcycle riders will question the strategy of utilizing only one lubricant for all three sumps and applications in their bikes.

When asking “what kind of oil should I use in my Harley Davidson?” the answer is not clear-cut because some riders may feel that a singular lubricant for all three sumps may not provide the type of protection they believe is necessary. They may have a difficult time believing that engine oil could also protect the primary chaincase and the transmission. For that situation, AMSOIL offers motorcycle riders specifically engineered Synthetic V-Twin Primary Fluid and Synthetic V-Twin Transmission Fluid.

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Differences Between the Two

Both Synthetic V-Twin Primary Fluid and Synthetic V-Twin Transmission Fluid have been engineered specifically to protect just one area of your bike instead of three. Custom formulating an oil for a specific area allows AMSOIL chemists to “over-engineer” each synthetic oil based on its specific application.

Synthetic V-Twin Transmission Fluid
AMSOIL Synthetic V-Twin Transmission Fluid

AMSOIL Synthetic V-Twin Primary Fluid has been “over-engineered” to provide maximum protection for primary chaincase components. It was formulated to have a viscosity similar to an SAE 50 engine oil. By designing this synthetic oil as a singular or straight weight lubricant, it naturally offers the benefit of being shear-stable over multi-viscosity oils. This approach allows the fluid to remain thicker, which in turn allows it to cling more effectively to the compensator without it being “flung off” as easily for the best amount of protection.

For Harley bikes, the compensator’s job is to perform as a shock absorber to help prevent engine vibration from affecting the transmission. When a compensator begins to wear, this can cause a ticking or knocking noise. Synthetic V-Twin Primary Fluid was also formulated to offer superior clingability to the chain for outstanding protection against wear. It also meets GASO MA/MA2 requirements for wet-clutch compatibility.

Synthetic V-Twin Transmission Fluid was engineered with a higher viscosity than the 20W-50 Synthetic V-Twin Motorcycle Oil. By creating a transmission fluid that is thicker or of higher viscosity, this delivers certain benefits such as helping to reduce noisy transmission gears and delivering much smoother shifts. This slightly thicker fluid film that is created on the gears provides some extra cushioning capabilities that translate into minimizing the loud “thunks” and gear noise.

Synthetic V-Twin Primary Fluid
AMSOIL Synthetic V-Twin Primary Fluid

Three Oils or One?

So what kind of oil should I use in my Harley Davidson? It depends on what is important to you. If you’re looking for convenience and simplicity, then following the recommendation of using AMSOIL 20W-50 Synthetic V-Twin Motorcycle Oil would be a good choice for an all-around lubricant. This is the best oil to use in Harley Davidson motorcycles and will provide outstanding protection in all three areas of your motorcycle.

For those riders who feel that it is better to use lubricants specifically designed for each area of the bike, and that want a lubricant that is dialed into those specific areas, then using each of the three application-specific synthetic lubricants in AMSOIL’s full line of V-Twin lubricants would fulfill that strategy. Regardless of which way you choose, the fact that you’re utilizing the finest synthetic oils on the market means that you can’t go wrong.

*All trademarked names and images are the property of their respective owners and may be registered marks in some countries. No affiliation or endorsement claim, express or implied, is made by their use. All products advertised here are developed by AMSOIL for use in the applications shown.

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