How does AMSOIL Perform in the Harley-Davidson® Milwaukee-Eight® Engine?

Harley introduced its Milwaukee-Eight V-twin engine in 2016,  in part to increase power and reduce engine heat. How does AMSOIL perform in this Harley engine?

First,  let’s cover the background story first. Harley interviewed 1,000 riders in seven cities to find out what they wanted in Harley’s next generation of touring bikes. Two themes emerged: more power and less heat.

Traditional air-cooled V-twin engines, like those used to power most Harleys, can get hot. In fact, some riders have complained about the intense heat radiating from the engine while riding, particularly the rear cylinder, which doesn’t receive as much airflow as the font cylinder.

Harley Davidson

The engine also suffers from heat

Extreme heat not only challenges rider comfort, it challenges the engine.

If, for example, extreme heat causes the piston to expand beyond acceptable tolerances, it can rub against the cylinder wall and cause scuffing.

Heat also causes some oils to thin and lose viscosity. The oil can become so thin the engine loses oil pressure, causing the oil-pressure gauge to bottom out.

The rider may notice increased valvetrain and gear noise as parts clatter together. Any rider worth his or her salt knows you don’t run an engine with no oil pressure, so he or she shuts it down until the engine cools enough to restore oil pressure.

Air ≠ liquid

Why do air-cooled V-twins get so hot? And how hot can they get?

It comes down to physics.

Air-cooled engines rely on air flowing over the engine to remove heat. In contrast, liquid-cooled engines, like those found on modern Indian motorcycles, use a coolant/water mixture to absorb engine heat and carry it to a radiator, where it dissipates into the atmosphere. 

Air is inherently less efficient removing heat than coolant/water, meaning your average V-twin powering a motorcycle runs hotter than a liquid-cooled bike.

In fact, our own extreme-heat testing at AMSOIL revealed the rear-cylinder temperature in a 2012 Harley Street Bob climbed as high as 550ºF (288ºC).

During testing of a 2017 Indian Scout, in contrast, we recorded an average cylinder temperature of 200ºF (93ºC). Granted, the bike didn’t undergo the same test as the Harley, meaning it’s not an apples-to-apples comparison, but it does suggest liquid-cooled bikes run quite a bit cooler than air-cooled bikes.

Riding conditions turn up the heat

Your riding conditions also affect engine heat.

Have you ever gone to Sturgis? Or ridden in a Fourth of July parade or other event at the height of summer?

In Sturgis, riders crawl down Main Street, taking in the sights and sounds. The August sun beats down on the asphalt and radiates onto the bike. Traffic can creep along so slowly that air doesn’t rush over the engine like it does when riding on the highway.

This lack of cooling air moving across the engine can cause heat to climb to dangerous territory.

If it’s bad enough, the electronic temperature controls that safeguard the bike against overheating can trigger, forcing the rider to pull over and stop until the engine cools.

The Harley Milwaukee-Eight runs cooler

I’m no marketing genius, but sitting alongside the road waiting for your bike to cool isn’t good brand strategy. So, the engineers at Harley designed the Milwaukee-Eight engine in part to run cooler.

Right on Harley’s website, the company presents the Milwaukee-Eight as the “…most powerful, coolest-running motor we’ve ever built.”

More power, less heat. Check.

AMSOIL and the Harley Milwaukee-Eight

Amsoil bought a 2019 Harley Street Bob with a Milwaukee-Eight 107 engine for extreme-heat testing. They wanted to see how AMSOIL 20W-50 Synthetic V-Twin Motorcycle Oil held up in Harley’s newest engine.

Prior to testing, Amsoil instrumented the bike and rode it on the streets to determine the operating conditions that would most severely challenge the bike and the motor oil.

As you might expect, stop-and-go, slow-moving traffic increased heat and presented the most severe conditions, similar to the conditions you see at a bike rally on a hot summer day.

So, Amsoil engineers designed a 1,000-mile dyno test meant to replicate the worst-case scenario: slow-moving operation in extreme heat with little-to-no cooling air passing over the engine. 1,000 miles is enough to make 640 trips down Main St. in Sturgis.

How does AMSOIL perform in the Harley Milwaukee-Eight?

The test created conditions that held the oil-sump temperature at a steady 300ºF (149ºC) for 1,000 miles. The rear-cylinder temperature surpassed 420ºF (216ºC). That’s hotter than your bike should ever get.

Amsoil test

Heat that extreme chemically breaks down most oils, causing it to lose viscosity and fall out of grade. It can also lead to oxidation, which hastens formation of harmful deposits that can cause the rings to stick, reducing compression and power.

After 1,000 miles of extreme heat, AMSOIL 20W-50 Synthetic V-Twin Motorcycle Oil delivered excellent protection.

Compare a brand-new rear-cylinder piston before the dyno test to one following 1,000 miles. It contains minimal deposits, the rings are free and it’s in great condition.

amsoil torture test

Chemical analysis following 1,000 miles at 300ºF (149ºC) shows the oil maintained viscosity and virtually prevented wear.

amsoil 1000 mile torture test

Check out the video to see the full results.

So, does the Milwaukee-Eight run cooler than past Harley V-twin engines? 

We’d have to do more testing to definitively say, but all signs point to the affirmative. Notice how the rear-cylinder temperature in our 2012 bike maxed out at 550ºF (288ºC), while the 2019 Harley maxed out just above 420ºF (216ºC). Bear in mind, however, that the two tests aren’t identical, meaning we can’t draw any firm conclusions. But it sure appears that Harley succeeded in reducing heat with its Milwaukee-Eight engine.

That’s thanks to a series of oil-filled cooling lines that circulate around the cylinders and carry heat to an oil cooler.

The oil in your bike should never get this hot. But, if it does, AMSOIL Synthetic V-Twin Motorcycle Oil has you and your Milwaukee-Eight engine covered.


What’s the best hydrostatic oil to use in a zero turn

What's the best hydrostatic oil to use in a zero turn

It’s that time of the year again and many of you may be wondering what’s the best hydrostatic oil to use in a zero turn.

Many mower manufacturers will allow the use of 20W-50 motor oil in their transmissions. While motor oil will work in many hydrostatic transmissions, there is a better option.

There’s no question that motor oil will capably work in mower hydrostatic transmissions. The mower will steer and it will be propelled forward and backward. But there are vital differences in the way that motor oil is formulated compared to dedicated hydrostatic transmission fluid. These differences can play a role in long term performance and component life.

The main factor to consider is that motor oil is designed for a completely different operating environment than hydrostatic transmission oil. Engine oils are formulated to deal with combustion and combustion by-products. There are very specific detergents and additives in motor oil that won’t affect performance or protection over the short term. But over time, these motor oil ingredients will limit the oil change interval and this can have an effect on long term component life.

The detergent ingredients in motor oil hold combustion by-products in suspension and prevent deposit formation. These ingredients are vital in an internal combustion engine. But not only are these ingredients not needed in a hydrostatic mower transmission, they can degrade and shear down over time. These degraded detergents can contribute to oil foaming, which can lead to compromised wear control.

Another advantage that a dedicated hydrostatic transmission oil has over motor oil is the ability to fight oxidation and corrosion. The hallmark of a good hydraulic fluid is oxidative stability and strong anti-corrosion chemistry. These attributes lead to longer service life and improved protection during storage.

Hydrostatic transmissions also have gears. The meshing of gears can shear down and thin out engines oils. Hydrostatic transmission oil is designed to withstand gear lubrication to a much greater extent than motor oil. This means that dedicated transmission oil has a superior ability to maintain its original viscosity and provide more reliable wear protection over the long term.


There’s no question that motor oil will work in mower hydrostatic transmissions that allow its use. But a dedicated hydrostatic transmission oil contains specific anti-foaming, anti-rust, anti-oxidation and anti-wear ingredients. This chemistry will allow for much longer service life, consistent performance and maximized transmission life. We recommend the new AMSOIL 20W-50 Zero-Turn Synthetic Hydrostatic Transmission Fluid.

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AMSOIL vs. Harley-Davidson SYN3

Check out how AMSOIL V-Twin Oil vs. Harley-Davidson SYN3 Performs

Bikers always want to know how AMSOIL products compare to the competition, particularly against Harley-Davidson oil. Read on to see how AMSOIL V-Twin Oil vs Harley-Davidson SYN3 compare.

It’s no wonder since Harley-Davidson dominates two-wheeled culture despite the resurgence of the Indian brand and the rising popularity of adventure bikes and everything you can do with them.

The company’s founding is a great story. William Harley and Arthur Davidson built their first motorcycle in a 10×15 shed right here in our home state of Wisconsin. While the duo’s 116-cc prototype bike lacked the power to ascend the hills around Milwaukee, it turns out it had the power to reshape American culture.

That’s one reason several AMSOIL Dealers and employees ride Harleys.

But, what about Harley-Davidson motorcycle oil?

To see how AMSOIL Synthetic V-Twin Motorcycle Oil performs vs. Harley-Davidson oil, check out the performance-test results for yourself.

Amsoil vs Harley SYN3

AMSOIL 20W-50 Synthetic V-Twin Motorcycle Oil resists viscosity breakdown 6X better that Harley-Davidson SYN3 Oil.*

Why viscosity matters

Viscosity is the most important property of a lubricant. While it’s defined as “resistance to flow,” it helps to think of viscosity as the oil’s thickness.

Your motorcycle engine, transmission and primary are designed to use oil of a specific viscosity, likely 20W-50 if you’re riding a Harley. The higher the numbers, the thicker the oil. So, a 20W-50 is thicker than the 5W-20 oil you use in your truck.

Oil that’s too thin reduces wear protection

Oil that’s too thin for its application won’t form a durable fluid film on metal components. The oil film protects the bearings from wear, helps keep the piston from scuffing against the cylinder wall, protects the transmission gears, guards against compensator wear and more.

In the transmission, for example, the oil must be thick enough to develop a strong fluid film to cushion the gears against shock-loading and quiet loud “thunks.” This promotes smooth, quiet shifts.

It’s the same story in the primary. The oil must protect the compensator from wear to prevent noise. If it doesn’t, you’ll find yourself on your phone reading the glut of content about Harley compensator noise and how to fix it.

The compensator acts like a shock absorber between the engine and transmission, helping prevent engine vibration from interfering with the transmission. When it wears out, it makes a ticking or knocking noise.

Avoiding this scenario seems easy enough – just use a good oil that maintains its viscosity and forms a strong, protective film on parts.

Motorcycles destroy lesser oils

That’s easier said than done.

Motorcycle engines, transmissions and primaries can be brutal environments that take a toll on oil. The mechanical shearing action of metal parts churning at thousands of rpm (particularly transmission gears) combined with extreme heat can cause oil to lose viscosity and become thinner.

Oil that’s too thin reduces wear protection and can lead to “thunking” transmission gears and a noisy compensator.

And nothing derails your pursuit of freedom on the open road like a noisy bike.

To help avoid these problems, use a motorcycle oil that maintains its protective viscosity, like AMSOIL 20W-50 Synthetic V-Twin Motorcycle Oil. Compared to Harley-Davidson SYN3 oil, it resists viscosity breakdown 6X better for improved protection against compensator and transmission gear wear.*

So, while we love Harley’s rich history of freedom and independence, we’ll stick with AMSOIL Synthetic V-Twin Motorcycle Oil over Harley-Davidson SYN3 oil.

AMSOIL V-Twin Oil vs. Harley-Davidson SYN3
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AMSOIL 15W-50 Metric Motorcycle Oil

AMSOIL 15W-50 Metric Motorcycle Oil

AMSOIL 15W-50 Metric Motorcycle Oil Takes Next Level Protection to Adventure-Bike Riders

Adventure bikes are prized for their versatility to cover just about any kind of terrain, opening riders up to new experiences. AMSOIL 15W-50 Metric Motorcycle Oil provides those benefits that help maximize the lives and performance of adventure-bike investments.

AMSOIL 10W-30 and 10W-40 Synthetic Metric Motorcycle Oils have been available for the unique needs of high-revving, hot-running metric motorcycle engines, particularly sport bikes like the Kawasaki* Ninja*, Yamaha* YZF and Honda* CBR; and touring bikes like the Honda Goldwing.* Now, AMSOIL 15W-50 Synthetic Metric Motorcycle Oil, product code MFF, is recommended for motorcycles that require 15W-50 motorcycle oil, including those made by Ducati*, BMW*, KTM*, Yamaha, Triumph* and Royal Enfield*.

The new 15W-50 Metric Motorcycle Oil is for certain touring bikes, particularly BMW and Ducati models, but it is primarily for adventure bikes, which are equipped for both on- and off-road riding. Popular examples include the BMW R 1200 GS Adventure, Triumph Tiger* 1200 XR and Ducati Multistrada* Enduro*.

AMSOIL 15W-50 Synthetic Metric Motorcycle Oil offers riders the security that comes with using an oil as precisely engineered as the bikes in which it’s used. It meets the exacting standards of industry and original equipment manufacturer (OEM) specifications. It is formulated to deliver the benefits riders most seek, including:

Robust power and acceleraton – By fighting wear and power-robbing carbon, AMSOIL Synthetic Metric Motorcycle Oil helps preserve engine power for maximum torque and acceleration. The oil’s precise frictional properties promote confident clutch feel, helping riders enjoy pinpoint control when staring from a dead stop and navigating terrain.

Next-level wear protection – Guarding against wear despite high RPM and intense heat results in long-lasting components that require less maintenance, letting riders focus on reaching their destinations, not fixing their bikes.

Fights extreme head – Resisting breakdown and maintaining viscosity in extreme heat offers excellent protection during longer drain intervals while preserving fuel economy.

Look up products for your bike here


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*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.

#1 product to keep Mud Off Your powersport toys

Mudslinger is the Number 1 product to keep Mud Off Your ATV & UTV.

If you spend your time racing down muddy trails or forging questionable terrain on your ATV, UTV, dirt bike, off-road truck or snowmobile (well, snowy trails for the latter), AMSOIL Mudslinger should definitely be a part of your arsenal.

This handy product will literally change your post-mudding experience. And, trust me, we know mudding. From sponsoring GNCC races on muddy courses in West Virginia, Indiana and elsewhere, to going off-road with Brad Lovell, the AMSOIL crew gets down and dirty with the best of them. So, we formulated Mudslinger with us and other mudders in mind.

What is Mudslinger?

Number 1 product to keep Mud Off Your ATV

Mudslinger is an aerosol that provides a protective, non-stick layer of armor against the accumulation of mud, dirt and snow on ATVs, UTVs, dirt bikes and snowmobiles. It makes removing mud and dirt with low-pressure water easy while protecting against UV rays and keeping equipment looking pristine. If you haven’t tried this standout product, here are a few ways (and reasons) to add it to your cart today and use it all year long.

Mudslinger is the Number 1 product to keep Mud Off Your ATV & UTV.

Mudslinger can help keep mud off your ATV/UTV or dirt bike. Here’s what a few riders and racers of off-road vehicles and powersports equipment have to say.

“I like getting my bike dirty, but I really don’t like cleaning it very much. Applied it to the rear wheel before the ride since that seems to be the dirtiest part of the bike most people see. Went for the ride, got the bike filthy, came home and washed it up. Probably 98% of the dust came off with using just the hose. This stuff works great for people who love getting their bikes dirty but hate cleaning them like me!”

“We are excited to try it out today to help keep the dirt and mud off the car during the triple crown race.”

Restore ATV/UTV, snowmobile or dirt bike luster

The sun’s UV rays slowly rob your powersports equipment of that light-new shine we all love. Mudslinger not only helps prevent accumulation of mud, dirt and snow, it provides a protective layer to counteract the damaging effects of UV rays. Its unique formulation restores, cleans and shines plastic, fiberglass and painted surfaces. Just spray it on a clean surface, allow it to sit for 15 minutes, then wipe off the excess with a lint-free microfiber towel for a brilliant shine.

Keep snow from sticking to your sled

Mudslinger is great for preventing the accumulation of snow, too. Before you take your snowmobile out on your next ride, apply Mudslinger anywhere you want to avoid snow buildup. Just make sure not to spray the seat or windshield.

Keeps car and truck tires clean

If you’re wondering if Mudslinger keeps tires clean, the answer is a resounding “Yes.”

Mudslinger can work on your daily driver or your prized car. Spray it on your tires to restore luster but also prevent the buildup of mud and snow. We recommend spraying it right after washing your car for the most protection.

Former NFL wide receiver and current outdoor enthusiast Jeff Janis uses it to keep the wheels clean on his truck and Chevy Camaro.

Jeff Janis mudslinger

Protect your snow blower from sticky snow

Winter means snow. Heavy, wet snow can plug the chute on your snowblower, wasting time and trying your patience. Not only that, freeing a blockage from the chute while the snowblower is running is dangerous. Before the snow hits and you pull your snowblower out, spray a coating of AMSOIL Mudslinger in the chute to help keep the snow flying all winter.

Protect your lawnmower

You can use Mudslinger to keep your lawnmower clean. After using Heavy-Duty Degreaser and a water hose to remove built-up gunk and grime, spray Mudslinger post-wash to protect your engine. The engine will literally look brand new.

Remember that next time you hit the rummage sales and find an old lawnmower with a good motor that just needs a little TLC.

How do you use Mudslinger?

Let us know in the comments below.

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Amsoil Firearm Cleaners and Protectants

Amsoil Firearm Cleaners and Protectants

Amsoil Firearm Cleaners and Protectants

Protection and Dependability

Nearly one in three Americans owns a firearm, typically falling into at least one of three categories. Hunters typically own shotguns to hunt waterfowl or upland birds and/or rifles to hunt larger game. Target/Sport Shooters own all types of firearms (shotguns, rifles, handguns) for recreational shooting. Firearms Professionals (gunsmiths, firearm safety instructors) work with all types of firearms in their professions.

The moving parts on firearms (actions, bolts, hinges) must be cleaned and lubricated to ensure top performance and long life. Hunters and shooters need their guns to perform when called upon, sometimes after an extended period of storage, after sitting for hours in a wet duck blind or while on a remote hunting trip with few opportunities to clean their gun daily. 

Since nothing will ruin a hunting trip or day at the range quicker than a malfunctioning firearm, we tested AMSOIL firearm products in a variety of handguns and long guns. The information we gathered, along with extensive testing in our chemical lab, resulted in products dialed in for outstanding firearm protection in the most demanding conditions. As seen in the image, AMSOIL Synthetic Firearm Lubricant and Protectant guards against damaging corrosion better than a leading competitor’s product, helping keep firearms working properly for generations.

AMSOIL Synthetic Firearm Lubricant and Protectant

AMSOIL Synthetic Firearm Lubricant and Protectant (FLPBA) effectively lubricates and protects guns, helping extend life and prevent blockage, jams and wear.

  • Outstanding protection and performance in both hot and cold climates
  • Specifically formulated for firearms, offering superior performance over multi-purpose products

AMSOIL Firearm Cleaner and Protectant

AMSOIL Firearm Cleaner and Protectant (FCPSC) is an aerosol cleaner and protectant that penetrates deep into hard-to-reach components, effectively cleaning residue from all surfaces and safely protecting guns for storage.

  • Effectively cleans fouling and powder residue from all firearm surfaces, reducing jamming and increasing reliability
  • Protects guns against corrosion, allowing for safe storage and preserving performance, reliability and value


AMSOIL Synthetic Firearm Lubricant and Protectant and AMSOIL Firearm Cleaner and Protectant provide premium protection and performance in all rifles, handguns and shotguns. Both are safe to use on all metals, woods, composites and rubbers.

Amsoil firearn spray cleaner

Penetrates deep into hard-to-reach components
Effectively cleans fouling and powder residue from all firearm surfaces, reducing misfires and increasing reliability
Protects guns against corrosion, allowing for safe storage and preserving performance, reliability and value
Amsoil firearm non spray cleaner
Penetrates deep into hard-to-reach components, effectively cleaning fouling and powder residue from all firearm surfaces, safely protecting them for storage, reducing jamming and increasing reliability. Protects against corrosion, allowing for safe storage and preserving performance, reliability and value.
Amsoil firearm spray lubricant
Effectively lubricates and protects firearms, helping extend life and prevent blockage, jams and wear. Outstanding protection and performance in both hot and cold climates. Specifically formulated for firearms, offering superior performance over multi-purpose products.
Amsoil firearm non spray lubricant
Effectively lubricates and protects firearms, helping extend life and prevent blockage, jams and wear. Outstanding protection and performance in both hot and cold climates. Specifically formulated for firearms, offering superior performance over multi-purpose products.
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7 Reasons to Register as an AMSOIL Commercial Account

7 Reasons to Register as an AMSOIL Commercial Account

7 Reasons to Register as an AMSOIL Commercial Account

Here are the 7 Reasons to Register as an AMSOIL Commercial Account. Owning and operating your own business leaves little time or energy for thinking about lubricants.

These days, trips to the store are unnecessary when you can place an order online with sites like Still not sold? Here are the top 7 reasons to sign up as an AMSOIL Commercial Account:

#1 AMSOIL Products Are Always On Sale

The term “Money over everything” resonates here. Business owners cannot afford to waste money in today’s competitive marketplace. AMSOIL commercial accounts can buy products at wholesale pricing, saving an average of 25 percent. Commercial accounts are also eligible for a purchase discount on product orders.

#2 Save on Maintenance Costs

Not only do commercial accounts save money buying AMSOIL products, they can also find extra savings by maximizing fuel economy and extending oil drain intervals with AMSOIL synthetic lubricants. Invest more money in growing your business, not repairing or fueling your equipment.

#3 Protect Your Investment

In the commercial world, vehicles and equipment are the major assets and investments. An excavator can cost as much as an HGTV-quality home. Yes, you can’t live in your excavator, but try building that home without an excavator for hire! AMSOIL products deliver proven wear protection in the most demanding equipment. AMSOIL products guard against wear and deposits, protecting equipment power and efficiency, which helps you get more work done and maximize engine and component life.

#4 Extensive Product Offering

AMSOIL offers everything from advanced synthetic drivetrain lubricants to premium fuel additives. We even have gun cleaner, leather boot lubemetal protector and several other products for just about anything in your garage. The complete AMSOIL product line ensures all your vehicles and equipment are protected. Not sure which lubricants your rig takes? Use the AMSOIL Lookup Guide.

#5 Personalized, Face-to-Face Service

Each commercial account is serviced by an independent AMSOIL Dealer. Dealers are available to help map out a program designed to maximize vehicle performance while saving you money. AMSOIL INC. corporate personnel are also available to offer technical and administrative support. Qualified accounts may also apply for credit with AMSOIL, simplifying the payment process.

#6 Free Maintenance-Tracking Program

MyAMSOILGarage™ is a free, easy-to-use online vehicle maintenance program. This free fleet-management tool allows you to organize your maintenance and service records. You can also schedule email reminders for future services and track any services that are performed. Visit MyAMSOILGarage to establish a free account.

#7 Signing up as a Commercial Account is FREE!

I have always liked saving the best for last. Establishing an AMSOIL Commercial Account is free and simple. AMSOIL is all about saving you time and money as a business owner. Why spend extra time or money repairing equipment when it could be avoided by using AMSOIL products.

Sign up today as an AMSOIL Commercial Account

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What’s the Difference Between Motorcycle, Dirt Bike and ATV Oil?

Amsoil Preferred Customer

Can I use the same motor oil in my motorcycle, dirt bike and ATV/UTV?

Sure, you can use a single oil formulation for all your toys (assuming you use the correct viscosity in each). But you shouldn’t. Kind of like you can dump Filippo Berio Extra Virgin Olive Oil into your machines, but you shouldn’t.

Why? Because each application presents unique challenges to motor oil that one formulation can’t meet. We’ll break them all down to see why.

But first, let’s look at what the motor oil must do regardless of the application.

Whether in a Harley-Davidson, Kawasaki sport bike, UTV or dirt bike, the oil has to protect against wear and fight the damaging effects of extreme heat. These include deposit formation, which robs the engine of efficiency and power. It also includes “oxidation,” which is a ten-cent word that means chemical break down. The sooner the oil breaks down, the sooner it fails to guard against wear and deposits as well as it should. And the sooner it requires changing, wasting time and money.

That’s simple enough. And years ago it was possible to make one motor oil to protect all those applications. But today’s engines aren’t so simple.

V-Twin Motorcycle

Take your classic air-cooled V-twin, like the engine found in most Harley-Davidson motorcycles. These engines get hot. How hot? In our 2012 Harley-Davidson Street Bob we tested in our mechanical lab, we saw cylinder temperatures reach 383ºF (195ºC). In contrast, our liquid-cooled 2017 Indian Scout running the same test demonstrated cylinder temps on average of 200ºF (93ºC).

Heat that intense can wreak havoc on the motor oil. The oil can lose viscosity and thin out, effectively turning your 20W-50 into a 10W-40, or worse. A lighter viscosity than what the engine is designed to use can fail to protect parts against wear. Extreme heat also hastens chemical break down.

In fact, the rate of oxidation doubles for every 18ºF (10ºC) increase in oil temperature. That means for every 18ºF increase in temperature, oil life is cut in half.

It’s vital that the oil meant for your air-cooled V-twin is formulated to withstand such intense heat. To accomplish that, we formulate AMSOIL Synthetic V-Twin Motorcycle Oil with added resistance to extreme heat. Its naturally heat-resistant synthetic base oils maintain viscosity despite extreme heat and the shearing force of transmission gears “cutting” the oil’s molecular structure. That translates into reliable protection in the toughest riding conditions.

Metric Motorcycle

What about a metric sport bike? Can’t be much different than a V-twin, can it?

In this case, foam is one of our biggest enemies. A metric bike can easily surpass 10,000 rpm. The mechanical action of the crankshaft spinning that fast can whip air into the oil, causing foam.

If the oil isn’t formulated with fast air-release properties, foam bubbles will travel throughout the engine. When they collapse between meshing gears or bearing surfaces, nothing is left behind to provide protection except air.

We all need air, but it’s worthless at protecting high-performance engines against wear.

That’s why we formulate AMSOIL Synthetic Metric Motorcycle Oil specifically to resist foam. Its anti-foam additives weaken the surface tension of air bubbles, helping eliminate foam. This results in excellent wear protection no matter how heavy you lay into the throttle.


Your ATV/UTV is a whole different animal. Here, oil film strength takes on additional importance. That’s because these units are frequently used to perform heavy work at slow speeds.

AMSOIL Synthetic ATV/UTV Motor Oil is engineered with robust synthetic base oils that allow formation of a durable protective film in the toughest conditions.

You might think, “Sure, but my Harley runs hard, too.” True, but motorcycles are typically ridden recreationally, meaning they undergo increased stress when accelerating, but level out so to speak once you reach cruising speed. Riding at a consistent speed under light load creates less stress than, for example, pulling a stump out of the ground with your UTV or pulling a loaded trailer uphill through the mud with your ATV.

Dirt Bike

Finally, we have dirt bikes. Surprisingly, dirt bike operating conditions are similar to those of an ATV or UTV. True, you don’t plow snow with your Honda CRF450. But the bike similarly undergoes low-speed stress punctuated with periods of high revving.

In a race, you’re heavy on the throttle out of the gate. Then you back off into the first corner. You’re on the throttle through the whoops, causing the rear tire to spin freely when it’s in the air, but create a heavy load on the engine when it contacts the ground.

Where dirt bikes differ, however, is in engine design.

Dirt bike engines are typically lightweight designs meant for performance. Any time you remove mass, yet increase power, you increase engine stress. The combination of high rpm and lighter materials creates the perfect scenario for engine failure should the motor oil fail to do its job. Plus, dirt bike pistons tend to have shorter piston skirts to reduce friction. That may help your lap time, but it doesn’t help engine longevity. The shorter piston wants to rock inside the cylinder, which concentrates tremendous force on the tiny area where the piston skirt and cylinder wall contact. Only a microscopic oil film provides protection in this area, meaning the oil had better offer the film strength needed to help the engine survive.

Making matters worse, dirt bikes barely hold any oil. Roughly one quart is common. Think about everything that single quart of oil must do:

  • Fight wear
  • Resist heat
  • Prevent deposits

That’s why most riders change motor oil frequently. Rebuilding the top-end every 15 hours or so isn’t uncommon, either.

But just because dirt bike oil is changed frequently, don’t think you can use a cheap oil. It’s far less expensive and less hassle to pay a little more up front for a good oil than it is to rebuild your top-end.

The moral of the story is this: the days of using one motor oil for all your toys is over. Each application creates unique challenges that are best suited for a tailor-made motor oil formulation.


How to Store Your Motorcycle for Winter

Unless you live in the deep south or you lost a bet, you’re not riding your motorcycle during the winter. Here’s how to properly store your motorcycle for winter to ensure it’s ready to go in the spring.

How to Store Your Motorcycle for Winter

1) Change the oil and filter

A minor debate exists in online forums over whether to change the oil and filter before you store your motorcycle or after you remove it from storage in the spring.

Change it before storage, and here’s why.

Engine operation produces combustion byproducts, such as moisture and acids. Those harmful byproducts can cause problems if they’re left in your engine during storage.

Moisture can lead to rust formation on engine parts. Once rust starts to form, it doesn’t stop. When you fire up the engine in the spring, rust particles can flake off into the oil and scour bearings and other parts during operation, leading to wear.

How to Store Your Motorcycle for Winter

Likewise, acids in the oil can cause problems. Acids corrode metal, which can lead to engine wear and, eventually, failure. It’s best to drain used oil from the engine prior to storage to prevent these potential headaches.

Fun fact: motor oil doesn’t naturally resist rust formation. Instead, special additives must be added to the formulation to guard against rust.

Not all motor oils contain enough rust inhibitors for storage, which is why it’s best to use a properly formulated oil specifically made for motorcycles.

2) Stabilize the fuel

While we’d all be doomed without oxygen, too much of it has a negative effect on gasoline.

Over time, gasoline oxidizes and breaks down. That simply means oxygen molecules alter the gasoline’s chemistry (think of a cut apple turning brown).

Oxidized fuel forms varnish, gums and insoluble debris that can clog tiny fuel passages in the carburetor and fuel system. This can lead to hard-starting and poor operation in the spring – assuming the engine starts.

Use a gasoline stabilizer to fight oxidation.

A good stabilizer resists oxidation to keep fuel fresh. For example, AMSOIL Gasoline Stabilizer keeps fuel fresh for up to 12 months. If you intend to store your motorcycle longer than four months, add Gasoline Stabilizer prior to the final outing of the season to ensure complete distribution throughout the fuel system.

AMSOIL Gasoline Stabilizer

AMSOIL Quickshot is another option. It’s primarily designed to clean fuel-system components and the combustion chamber while addressing ethanol problems. But it’s also formulated with a stabilizer that keeps fuel fresh during short-term storage of up to four months.

AMSOIL Quickshot

3) Maintain the battery

There are a couple ways to maintain the battery.

You can remove it from the bike and store it where it won’t freeze, like a basement or heated garage. Make sure to store it off the ground.

You can also leave the battery in the bike. Whichever works best, be sure to attach a trickle charger to the battery. It automatically maintains the optimal charge throughout the storage period. That way your bike will fire right up in the spring.

4) Wash and dry the motorcycle

Wash all the dirt, dust and bugs from the bike before storing it for the season. Use a mild soap and a sponge. A brush works well for wheel spokes, but avoid using a stiff brush to clean areas where you might scratch the finish. Rinse and dry with a clean cloth or chamois.

Avoid getting water into the pipes. If you do, start the bike and run it until it’s warm to evaporate accumulated water.

5) Cover and store your motorcycle

Once the bike is dry, cover it with a quality dust cover, even if stored indoors. You can also block the pipes with rags or dryer sheets to deter mice or other pests from colonizing the exhaust pipes. Just remember to remove them before starting the bike.

And that’s how to Store Your Motorcycle for Winter.

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What is Fuel Stabilizer?

What is fuel Stabilizer and what does it do? You probably know you should stabilize fuel before placing your lawnmower, motorcycle, classic car or other vehicles and equipment into storage for the season. Maybe you learned the lesson the hard way after tearing a rotator cuff trying to start a lawnmower or snowblower after several months in storage minus stabilized fuel. So, what is fuel stabilizer and what does it do?

Time degrades gasoline

Just about everything deteriorates over time, including the fuel that powers your vehicles and equipment. In fact, gasoline can start to break down in as little as 30 days. Deposits can form that prevent the engine from starting, like those shown in this carburetor bowl.

What is Fuel Stabilizer and what does it do?
Bad gasoline is the number-one reason seasonal equipment starts hard or runs rough.

Over time, gasoline changes, leaving behind gums, varnish and other solids that foul the fuel system and prevent gas from flowing into the combustion chamber. In severe cases, gasoline can change so dramatically that it no longer ignites.

Gasoline is predominantly a mixture of carbon and hydrogen atoms bonded together into energy-dense hydrocarbons. Like conventional base oils, it’s derived from crude oil via a distillation process that uses heat, pressure and other catalysts to create different fractions. Gasoline is comprised of hydrocarbons that are lighter than those found in, for example, diesel fuel or conventional base oils. Refiners add ethanol to the formulation, typically 10 percent, but as high as 85 percent. Time, however, takes its toll on gasoline. Exposure to heat, humidity, atmospheric pressure, oxygen and other variables degrades fuel.

Fuel degrades more quickly than oil

In addition to gums and varnish becoming more concentrated and less soluble as lighter hydrocarbons evaporate, gas is continually oxidizing, which further contributes to varnish and other gunk.

Gasoline oxidizes more quickly than motor oil and its negative effects are more immediately noticeable. That’s why it’s important to use high-quality gas and store it in approved containers where air infiltration is limited, like inside a ventilated garage or shed, and not in the back of your truck or under the deck.

Meanwhile, ethanol added to gasoline at the refinery can absorb water from the atmosphere, which can lead to phase separation, which occurs when ethanol and gas separate, much like oil and water. Ethanol that has absorbed enough moisture and has sat long enough can foul the fuel system and prevent the engine from starting.

That’s why it’s vital to stabilize fuel prior to storage.

Personally, I add gasoline stabilizer to my five-gallon gas can at every fill-up. That way I never worry about fuel going bad inside my four-wheeler, lawnmowers, chainsaws and other equipment around the homestead.

What is Fuel Stabilizer and what does it do?

But what, exactly, does fuel stabilizer do? Let’s use an analogy to explain.

You’ve probably heard terms like “free radicals” and “antioxidants” in relation to your health. A free radical is an unpaired electron, and most are unstable and highly reactive. They can either donate an electron to, or accept an electron from, other molecules. This starts a chain reaction that can lead to oxidative stress and cell damage. Left unchecked, free radicals can lead to health problems, like cardiovascular disease and cancer.

To help fight free radicals, we should eat plenty of foods rich in antioxidants, which lessen their effects. Antioxidants can “donate” an electron to free radicals or trap them, effectively reducing their instability without becoming unstable themselves. Antioxidants aren’t silver bullets, but they go a long way toward improving our health.

By analogy, fuel stabilizer is an antioxidant for your gasoline. It disrupts the free-radical-induced chain reaction that causes gas to oxidize and form varnish and gums. Some stabilizer products, like AMSOIL Quickshot, also contain chemistry that increases solvency and breaks down existing varnish, helping clean a dirty carburetor and restore performance.

How does AMSOIL Gasoline Stabilizer stack up?

Very well, thanks. But don’t trust me, trust the independent test results shown below.

Amsoi gasoline Stabalizer
What about protection against corrosion? Again, AMSOIL delivers, as shown here.
Amsoil vs Seafoam
So, if it’s formulated properly, like AMSOIL Gasoline Stabilizer, fuel stabilizer improves the stability of gasoline to protect against varnish and gum formation so your vehicles and equipment fire to life when you take them from storage. AMSOIL Gasoline Stabilizer also protects against corrosion during storage to maintain fuel-system cleanliness while stabilizing fuel for up to 12 months.
amsoil Stabilizer
Buy Fuel Stabilizer

For short-term storage up to six months, consider AMSOIL Quickshot. It also contains chemistry that increases solvency and breaks down existing varnish, helping clean a dirty carburetor and restore performance.

Amsoil Quickshot
Buy Quickshot

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