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Motorcycle Oil, Primary Fluid & Transmission Fluid: What’s The Difference?

Written by Charleen

The Fool Said I Can Use 20W-50 In All Three. What?

Some V-twin motorcycles, like modern Indian  and Victory  bikes, use a shared sump, meaning they use the same lubricant in the engine, transmission and primary chaincase. Most Harley Davidson motorcycles, however, use a separate sump for each lubricant. This presents Harley (Don’t forget about Davidson) owners with a choice: Use the same lubricant in all three areas of the bike, or use a separate lubricant formulated and labeled for each area. Here, we offer guidance for deciding what’s right

For the record, AMSOIL recommends AMSOIL 20W-50 Synthetic V-Twin Motorcycle Oil (MCV) in the engine, transmission and primary chaincase on most Harleys (consult the Motorcycle Product Guide at amsoil.com for specific recommendations). It offers…

  • Convenience. Riders buy and install one lubricant. This reduces cost and results in fewer half-used bottles of oil lying around the garage.
  • Simplicity. Remembering to buy one lubricant is far easier than remembering three.
  • Great all-around performance in all three areas of the bike.
  • It’s what the upper brass at AMSOIL use in their bikes.

We formulate 20W-50 Synthetic V-Twin Motorcycle Oil to be an excellent all around lubricant. It delivers outstanding engine protection due to its proven ability to fight wear, reduce heat, maintain cleanliness and prevent corrosion during storage.

See why the 50 weight qualifies as a 90 in the transmission. 

Synthetic V-Twin Motorcycle Oil also boasts a shear-stable formulation. It resists viscosity loss despite the intense pressure and churning action of high RPM transmission gears, allowing it to deliver reliable transmission protection. Synthetic V-Twin Motorcycle Oil meets JASO MA/MA2 standards and is wet-clutch compatible for excellent performance in the primary chaincase. Its frictional properties are dialed-in to allow the clutch plates to engage and disengage without loading or slipping for smooth shifts.

Despite these benefits, some riders question the practice of using one lubricant in all three areas of their bikes. They have a difficult time accepting that a motor oil can also protect the transmission and primary chaincase.

I don’t think so. My Mechanic always said you have to use different oils.  – That’s partially true…

If you believe this to not be true we make the separates for you. Debate free oil options! And yes, they are more dialed in.. This is why we offer Synthetic V-Twin Transmission Fluid (MVT) and Synthetic V-Twin Primary Fluid (MVP).

What are the differences?

In essence, Synthetic V-Twin Transmission Fluid and Synthetic V-Twin Primary Fluid are formulated to protect just one area of your bike rather than three. This specificity allows us to engineer each lubricant for its precise application.

Transmission Fluid

Synthetic V-Twin Transmission Fluid has a higher viscosity than 20W-50 Synthetic V-Twin Motorcycle Oil. A higher-viscosity, or “thicker,” lubricant can help quiet noisy transmission gears and enable smooth shifts. The lubricant develops a slightly thicker fluid film on gears, which provides cushion to help diminish loud “thunks” and gear noise.

Again, we realize that’s what people want and in some cases it’s beneficial to the gears but it’s slightly thicker than the OEM specifications or better put – on the high side of the range. The only real downside other than cost is less efficiency in cooler weather and a change in overall MPG.

Primary Fluid

Likewise, AMSOIL Synthetic V-Twin Primary Fluid is designed only to protect primary chaincase components. Its viscosity is similar to an SAE 50 motor oil. Formulating it as a straight-weight lubricant naturally offers an advantage in shear stability over other multi-viscosity lubricants. (AMSOIL 20W-50 Synthetic V-Twin Motorcycle Oil is absolutely shear stable and will not thin out from mechanical activity.) This helps the fluid remain thicker, which helps it cling to the compensator without being “flung off” as easily for maximum protection. In Harleys, the compensator acts as a shock absorber to prevent engine vibration from affecting the transmission. Compensator wear often leads to a knocking or ticking noise.

Synthetic V-Twin Primary Fluid also clings well to the chain for excellent wear protection. And its wet-clutch-compatible formulation meets JASO MA/MA2 requirements.

Many buy this because some bikes have issues shifting back to neutral. AMSOIL Primary Oil makes it much easier for the linkage to catch neutral when you need it.

One oil or three?

So, which is the better route for Harley owners? Either way you can’t go wrong but examine if you identify with the issues requiring the 2nd choices.

For riders who desire the simplicity and convenience of using one lubricant for all three areas, following our primary recommendation of 20W-50 Synthetic V-Twin Motorcycle Oil in all three areas is the best choice.

For riders who prefer lubricants dialed in for each area of their bikes and don’t mind a few extra bottles of oil lying around the garage, steer them toward our full line of V-twin lubricants.

Either way, they can’t go wrong. 

Ordering 605-274-2580

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Why are We Tearing Apart this Indian Scout?

Written by Charleen

Why are We Tearing Apart this Indian Scout?

(Plus, Check Out this New Product now in Sioux Falls)

 John Baker|

Motorcycles occupy a prominent place in our national lore. The V-twin engine, one can argue, belongs in our menagerie of quintessentially “American” items, right next to the bald eagle, the Liberty Bell and Abe Lincoln’s stovepipe hat.

It’s easy to see why. Motorcycles stand for freedom, rebellion, power. For many Americans (like Guinness World Record holder Danell Lynn), a motorcycle is their weapon of choice to fight the specter of an unlived, ordinary life.

One of the best…

Most opt for a Harley-Davidson, whose engines have provided the soundtrack of the American summer for decades. It’s impossible to drive through just about any paved corner of America and not hear the rumble of a Harley. The brand is so firmly entrenched in our psyche that, for many, “Harley” has become the generic term for “motorcycle,” the way “Coke” stands for any soft drink in the South.

Not bad for a company founded in a little shed in Milwaukee, Wis., in 1903.

…but not the first

But for all Harley’s fame, the company can’t lay claim to being the first American motorcycle company. That distinction goes to Indian, founded just two years earlier, in 1901. Throughout the 1910s, Indian was the largest motorcycle manufacturer in the world. The Indian Scout and Chief gained huge popularity throughout the early 20th Century.

But financial trouble eventually beset the company, and Indian ceased production in 1953. One of America’s definitive brands shuttered its doors.

Flash forward to 2011, when Polaris Industries, better known around here for making snowmobiles, bought the brand and injected into it new life…and money. The Chief is back. So is the Scout, which was unveiled in Sturgis in 2014. Motorcycle.com named the Scout its 2015 Motorcycle of the Year.

Today, with sales of V-twins stagnant industry-wide, the Scout has bucked the trend, thanks to its classic styling and lightweight chassis powered by a 100-hp V-twin.

Let the testing begin

This preamble isn’t meant as a commercial for Indian. It’s meant to add context to this Indian Scout that rolled into our mechanical lab earlier this year.


While one look entices most people to jump aboard and hit the streets, it beckons us to drive right into our dyno cell for a few rounds of testing. In fact, this 2017 Scout is replacing our 2012 Harley-Davidson Street Bob, which has accumulated 207,111 miles over the past few years in all kinds of engine testing.

Why the Indian? For starters, we simply like testing things around here. Our mechanical lab is a who’s who in the world of engine and equipment manufacturers. Adding Indian components to our collection of Harley, GM, Stihl, Honda and other parts seemed to fit the bill.

More importantly, we just introduced new AMSOIL 15W-60 Synthetic V-Twin Motorcycle Oil, and it’s recommended for the Indian Scout (along with Victory motorcycles). We already know the formulation works great in the Scout, but we’re never satisfied with “good enough” around here. This bike gives us our own “proving grounds” in which to test, tweak and re-test our formulations. So, in the months ahead, the Scout’s 1133-cc V-twin will be rumbling away in our mechanical lab under the watchful eyes of our technicians.

Once the tests end, the real fun begins –tearing down the engine and examining the pistons, rings, cylinders and other parts. One of my tasks here at AMSOIL is to assist in documenting some of our testing, so I plan to get awfully familiar with the guts of this Scout in the days ahead.

Hopefully we’ll have some interesting results to share soon, so stay tuned.

Until then, get out and ride.

Upgraded Protection for Indian Scout, Victory Motorcycles

 

New AMSOIL 15W-60 Synthetic V-Twin Motorcycle Oil expands the AMSOIL V-twin motorcycle oil product line. It is recommended for the popular Indian* Scout* and all Victory* motorcycles.

Fights heat and wear

Like the rest of the AMSOIL V-twin line, 15W-60 Synthetic V-Twin Motorcycle Oil is designed to resist extreme heat and deliver excellent wear protection. Summer riding can cause engine temperatures to skyrocket, especially in slow-moving rally or parade traffic. AMSOIL 15W-60 Synthetic V-Twin Motorcycle Oil’s outstanding heat resistance helps bikers ride with confidence in the most extreme conditions.

Why is extreme heat so bad for motorcycles?

High heat causes the pistons to expand, potentially leading to catastrophic scuffing and cylinder wear. It also hastens oil breakdown – the rate of oxidation doubles for every 18°F increase in temperature. Oil that has oxidized leads to performance-robbing deposits.

In V-twins, especially air-cooled models, the oil plays a vital role in carrying away heat and dissipating it into the atmosphere via the oil pan or oil cooler. AMSOIL Synthetic V-Twin Motorcycle Oil withstands intense heat, helping your bike last longer and run better.

Helps ease shifting

Riders also like to use an oil that helps deliver smooth shifts. Here again, AMSOIL 15W-60 Synthetic V-Twin Motorcycle Oil delivers. Its wet-clutch-compatible formulation contains no friction modifiers and promotes smooth shifts, helping riders avoid killing the engine.

Find AMSOIL Products for my Motorcycle

*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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