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Your Manufacturer’s Warranty is Secure

Your Manufacturer’s Warranty is Secure and better protected with AMSOIL

AMSOIL lubricants maintain your factory vehicle and equipment warranties.

_by David Hilgendorf October 24, 2022

According to the Federal Trade Commission, manufacturers or sellers may make promises to stand behind the products you purchase. Any warranty offered must be available to read before purchase, so be sure to understand the details of what is covered before you buy.

Vehicle and equipment warranties often cover the expensive costs of labor and parts necessary to fix certain product defects or malfunctions within a predetermined amount of time or usage. It is important to know that your manufacturer’s warranty is secure for peace of mind.

Whether investing a few thousand dollars in lawn equipment, tens of thousands on powersports vehicles that may only be used a few months out of the year, or buying a new car or truck for daily use, manufacturers know these are big investments. They put a lot of focus on warranties to build consumer confidence and want you to buy their brand of parts and lubricants instead of aftermarket products.

Feeling pressured to use their products?

Some original equipment manufacturers (OEMs) falsely claim that you must use their brand of parts and lubricants or risk voiding your factory warranty. OEMs may even attempt to make you feel like they control what you can do with your vehicles. This is one of the biggest hurdles faced when recommending AMSOIL.

Thankfully, in America, the Magnuson Moss Warranty Act [15 USC Ch. 50 §2302(c)] protects your freedom to choose any brand of aftermarket parts and lubricants and your right to extend oil-change intervals beyond what is recommended in your owner’s manual, without voiding your warranty. Similar protections are available in Canada.

U.S. Federal law Protects you

Here are key points to remember for maintaining your factory warranty:

  • It is illegal to tie warranty coverage to the brand of parts or lubricants you use unless the manufacturer provides the parts or lubricants free of charge.
  • You have freedom to choose how to protect your vehicles and equipment, including extending recommended drain intervals.
  • Manufacturers can’t deny warranty coverage without proving an aftermarket part or lubricant caused a failure.

If anyone tries to tell you differently, contact the FTC at

Tips to avoid warranty issues

No one wants to file a warranty claim. It’s a hassle and can take months to resolve. Here are a few tips to help smooth the process should you ever need to use your factory warranty.

  • Read your warranty. Familiarizing yourself with what is and is not covered is worth your time.
  • Period of coverage. If your vehicle or equipment acts up, have it looked at before the end of the warranty term.
  • Service records and receipts. No matter who performs the service, providing proof that you maintained your vehicle removes the easiest way for manufacturers to shirk responsibility.
  • Speak up. If you think a service adviser denied your warranty claim unfairly, ask to speak with a supervisor. If the dealer does not resolve the issue, try another dealer, or contact the manufacturer. If you still aren’t getting results, contact your attorney general, local consumer protection office or the FTC.
  • Avoid aftermarket warranties. Many are scams. If a dealership is selling one please check the BBB looking up the company first! I can bet there are a lot of angry customers! If you think it’s legit remember it’s a contract and NOT a warranty so be sure to have them add in that you are going to use AMSOIL on your terms.

Strong products, strong warranty

AMSOIL designs high-performance replacements for manufacturer-branded lubricants that keep your factory warranty intact.

AMSOIL developed Warranty Secure branding to simply and effectively reinforce your right to use AMSOIL synthetic lubricants. We use clear, direct language to remind consumers that the law is on their side and to dispel fears generated by misleading or false warranty claims from any manufacturer, dealer or mechanic.

Because this issue is more prevalent in the powersports market, the Warranty Secure icon appears on all our powersports products, including AMSOIL Synthetic V-Twin Motorcycle Oil and ATV/UTV oils.

AMSOIL also offers its own Limited Warranty, offering an extra measure of protection. While some oil companies guarantee their products only for a specified mileage, we stand behind our products for as long as you use them.

Runs on Freedom™ Snowmobile Warranty

Additionally, AMSOIL offers the revolutionary Runs on Freedom Snowmobile Warranty offering complete peace of mind. Simply use AMSOIL INTERCEPTOR Synthetic 2-Stroke Oil exclusively in your new sled and we’ll cover any engine repairs for up to two years or 5,000 miles (8,000 km). Read the terms and conditions and register your sled today!

No other aftermarket snowmobile lubricant manufacturer offers this robust of a warranty. We’re so confident in our products, we’ll cover any repair to your snowmobile engine in the unlikely event of an engine failure. This means AMSOIL may end up fixing defective OEM parts that fail for reasons unrelated to our oil, but we’re more concerned about protecting our customers and their machines.

As millions of satisfied AMSOIL customers know, using AMSOIL synthetic lubricants or practicing extended drain intervals does not void vehicle or equipment warranties.

AMSOIL stands behind its products and the people who use them. If the OEM claims use of AMSOIL products violates the warranty, contact AMSOIL Technical Services (715-399-8324) or visit


How Often Should I Change Differential Fluid?

How Often Should I Change Differential Fluid?

Fluid change intervals depend on your vehicle, driving conditions and gear oil quality.

_by David Paiuilldorf | july 26, 2023

A differential is a set of gears that allows a vehicle’s driven wheels to revolve at different speeds when going around corners or over rough terrain. Those gears require lubrication, which is commonly called differential fluid, gear oil, or gear lube.

How often you should change differential fluid depends on your vehicle, driving conditions and fluid quality. If you drive primarily on the highway in temperate conditions and rarely tow or haul, you won’t need to change the differential fluid very often.

However, severe operating conditions break down differential fluid more quickly and place greater stress on the gears and bearings, inviting wear that reduces their lifespan.

Greater load capacity, less lubrication.

Truck manufacturer’s ongoing arms race for the highest towing capacity has resulted in trucks that place more stress on differentials than their predecessors. Meanwhile, differential fluid capacities have largely decreased or remained the same.

For example, compare a 1996 Ford F-250* Crew Cab to the 2021 version. Back in 1996, maximum towing capacity was 10,500 lbs. using a rear differential that held 3.75 quarts of gear oil. The 2021 model offers up to 15,200-lb. towing capacity using a rear differential that holds between 3.3 and 3.5 quarts of fluid.

This means less lubrication is responsible for protecting gears among higher heat and stress. In this environment, inferior lubricants can shear and permanently lose viscosity. Once sheared, the fluid film weakens, ruptures and allows metal-to-metal contact, eventually causing gear and bearing failure. That’s not good!

Increased temperatures in differential

As temperatures rise, lubricants lose viscosity and the extreme pressure between gears can shear the lubricant film, causing increased metal-to-metal contact, friction and heat. Friction and heat create a vicious cycle known as thermal runaway that spirals upward, leading to increased wear and potential gear failure.

Oh and let me tell you a quick story about AMSOIL diff fluid. Under thermal runaway the heat causes the gears or metal to expand just enough to act like a brake. We’ve had RVs comment on reaching 5 to 7 more miles per hour on mountain passes due to the reduction of heat using the AMSOIL Severe Gear. See what I’m saying?

Severe Service Differential Fluid Solution

If you drive via Severe Service towing conditions or haul heavy loads frequently, especially in warmer temperatures, most manufacturers recommend changing the differential fluid more often, sometimes as often as every 30,000 miles. This applies to most work trucks and anyone who pulls a camper, boat or trailer regularly

The best way to determine the recommended mileage interval for differential fluid changes is to check your owner’s manual. Use a high-quality synthetic gear oil to reduce gear wear and maximize your vehicle’s ability to tow and haul.

Amsoil’s Severe Gear Squeeze or Easy-Pack

Amsoil Squeeze Packs cut the differential oil change process in half!

AMSOIL SEVERE GEAR Synthetic Gear Lube is specifically designed for severe service. It maintains viscosity better than other gear lubes under rigorous use and contains advanced anti-wear additives for additional protection.

SEVERE GEAR often costs less than OEM-branded gear oil, and the AMSOIL Easy-Pack or I call Squeeze Pack eliminates the frustrations of changing gear oil. Its flexible design lets you easily reach inconvenient fill holes and squeeze all the gear lube out of the package. Less mess, less waste, less frustration.

And hey, by the way most auto parts stores don’t even carry a known name brand GL5 gear lube these days. Tell your auto parts store to PLEASE carry AMSOIL as it’s about the only real performance player out there and the only one that really works..



Can I Use Transmission Fluid in Oil to Clean My Engine?

Can I Use Transmission Fluid in Oil to Clean My Engine?

Yeah – those youtube rescue channels all show using ATF to clean out the engine – they’re doing it the hard way…

ATF is not made to clean sludge from engines. Instead, it’s best to use a dedicated engine flush.

AMSOIL Engine & Transmission Flush helps to remove sludge and deposits from engines and transmissions.

_by Phil Collinsburger |May 5, 2022

Over time, engines can accumulate deposits that reduce power and performance. Since automatic transmission fluid contains detergents to clean sludge, some DIYers add a small amount of transmission fluid in their oil to clean the engine prior to oil changes.

ATF, however, is not formulated for use in automotive engines. Instead, a product that’s designed to flush engines is a far-superior approach.

How Sludge Forms

Stop-and-go driving, prolonged idling, trips too short for the engine to reach full operating temperature, towing, the ingestion of airborne dirt, fuel dilution, water condensation and oxidized oil all can promote sludge build-up in motor oil and transmission fluid.

Sludge clogs narrow oil passages, restricting oil flow to vital parts, especially the upper valve train area, causing wear.

Transmission Fluid In Oil Reduces Cleaning Power

In most cases, adding automatic transmission fluid to motor oil reduces cleaning power. That’s because the detergency of ATF is less than motor oil. Why is that?

ATF is exposed to lower levels of combustion byproducts and contaminants than motor oil, so it is formulated with reduced detergency. Instead, ATFs have elevated levels of friction modifiers and other additives that help protect gears and clutches.

Transmission Fluid In Oil Reduces Wear Protection

Second, adding ATF alters the motor oil formulation and reduces its effectiveness.

A good motor oil is a fine balance of base oils and additives designed to fight wear, reduce friction, prevent deposits and slowly dissolve accumulated sludge. The cleaning power of motor oil is designed to work gradually over subsequent oil changes and not necessarily all at once. Adding a foreign substance to the oil disrupts the formulated chemistry, negatively impacting wear protection, detergency and more.

Changes Motor Oil Viscosity

Finally, ATF can alter the viscosity of the oil, reducing wear protection.

Viscosity is the oil’s most important property, influencing wear protection and fuel efficiency. Increasing or decreasing viscosity by adding a little transmission fluid in oil to clean sludge can lead to increased engine wear.

Use An Engine Flush Instead

If you want effective sludge removal and cleaning power, we recommend using AMSOIL Engine & Transmission Flush. It helps to restore fuel economy, increase operating efficiency and reduce emissions in gasoline and diesel engines, and automatic transmissions. Its potent, detergent-based formula cleans sludge and deposit build-up.

AMSOIL Engine & Transmission Flush

  • Prepares engines and transmissions for new oil
  • Removes deposits and sludge for improved efficiency, fuel economy and lower emissions
  • Prolongs vehicle life
  • Detergent-based formula is environmentally friendly
  • Compatible with seals and gaskets
  • Works in one treatment
  • Easily disposed of with waste oil

Benefits For Gasoline And Diesel Engines

  • Helps loosen sticky valves and rings, minimizing blow-by and reducing emissions
  • Helps quiet lifter noise
  • Promotes lower operating temperatures through sludge removal

Benefits For Automatic Transmissions

  • Cleans deposits in oil cooler and ports
  • Helps unclog fluid passages
  • Cleans deposits and varnish from clutch plates, helping improve efficiency
  • Promotes smoother operation and transmission life through reduced shift delay

Gear Oil vs. Engine Oil: What’s The Difference?

Gear Oil vs. Engine Oil: What’s The Difference?

Gear oil uses a different viscosity classification and different additives.

by Joel Youngman|May 9, 2022

High-quality gear oil must lubricate, cool and protect geared systems while carrying damaging wear debris away from contact zones and muffling the sound of gear operation. In this post, we’ll look at the differences between gear oil vs. engine oil.

Differentials, manual transmissions and industrial machinery gears often require protection under extreme temperatures and pressures to prevent wear, scuffing and other damage that results in equipment failure. Protection against oxidation, thermal degradation, rust, copper corrosion and foam is also important.

Gear Oil vs. Engine Oil: Viscosity Comparison

Gear oil differs from engine oil. While many motorists may assume SAE 90 gear oil is thicker than SAE 40 or 50 engine oil, their viscosities are the same, as this gear oil viscosity chart shows.


One major difference between the two are in the additives they use.

Motor oil contains additives such as detergents and dispersants to combat byproducts from gasoline or diesel ignition. Because an internal combustion engine has an oil pump and lubricates the bearings with a hydrodynamic film, extreme-pressure additives such as those used in gear oils are not necessary.

Gear Oil Undergoes Boundary Lubrication

Engine oils and gear oils both have anti-wear additives, and they both must lubricate, cool and protect components. Gear oils, however, may be placed under extreme amounts of pressure, creating a propensity for boundary lubrication, a condition in which a full-fluid lubricating film is not present between two rubbing surfaces.

For example, differentials in cars and trucks have a ring-and-pinion hypoid gear set. A hypoid gear set can experience boundary lubrication, pressures and sliding action that can wipe most of the lubricant off the gears. Extreme-pressure additives are used in gear oil to combat this extreme environment.

Gear Oil vs. Engine Oil: Additional Differences

Rust & Corrosion Protection

Because many of the components found in the drivetrain consist of ferrous material, gear oil must prevent rust and corrosion to other materials. Rust and corrosion problems are not nearly as prevalent in engines.


The many small and intricate components that make up gear sets can be quite noisy and may be subjected to shock-loading, which occurs when components are quickly placed under intense load, like when accelerating with a powerful engine.

The viscosity and extreme-pressure formulation of gear oil quiets gears and dissipates shock-loading.


The rotating motion of gears also tends to churn the lubricant, leading to foam. If a gear oil foams, its load-carrying capacity is significantly reduced because the air suspended within the oil is compressible.

For example, when the gear teeth contact, any trapped air bubbles compress, reducing the thickness of the separating oil film. In turn, this reduction could lead to direct metal-to-metal contact between gear teeth and result in accelerated wear.

Typical Drivetrain Fluid Additives

Much like with motor oil, the additives included in gear oil either enhance existing properties or impart new ones. Drivetrain-fluid additives include the following:

  • Extreme-pressure and anti-wear agents minimize component wear in boundary lubrication situations.
  • Pour-point depressants improve low-temperature performance.
  • Rust and corrosion inhibitors protect internal components.
  • Oxidation inhibitors reduce the deteriorating effects of heat, increasing the oil’s service life.
  • Viscosity index improvers allow a lubricant to operate over a broader temperature range.
  • Anti-foam agents suppress foam and dissipate entrapped air.
  • Friction modifiers – The required degree of friction-reduction can vary significantly between different pieces of equipment in drivetrain applications. In some cases, friction modifiers may be required to obtain the desired results.

Common Gear Designs

Gear designs vary depending on the requirements for rotation speed, degree of gear reduction and torque-loading. Transmissions commonly use spur gears, while hypoid-gear designs are usually used as the main gearing in differentials. Common gear types include the following:

Spur Gears

Spur (straight-cut) gears are widely used in parallel-shaft applications, such as transmissions, due to their low cost and high efficiency. The design allows the entire gear tooth to make contact with the tooth face at the same instant. As a result, this type of gearing is subjected to high shock-loading and uneven motion. Design limitations include excessive noise and a significant amount of backlash during high-speed operation.

Bevel Gears

Bevel (straight- and spiral-cut) gears transmit motion between shafts that are at an angle to each other.

Primarily found in industrial equipment, as well as some automotive applications (differentials), they offer efficient operation and are easy to manufacture.

As with spur gears, they are limited due to their noisy operation at high speeds and are not the top choice where load-carrying capacity is required.

Worm Gears

Worm gear sets employ a specially machined “worm” that conforms to the arc of the driven gear. This design increases torque throughput, improves accuracy and extends operating life.

Primarily used to transmit power through nonintersecting shafts, this style of gear is frequently found in gear-reduction boxes as it offers quiet operation and high ratios. Its downfall is its low efficiency.

Hypoid Gears

Hypoid gear sets are a form of bevel gear, but offer improved efficiency and higher ratios over traditional straight-bevel gears. Commonly found in axle differentials, hypoid gears are used to transmit power from the driveline to the axle shafts.

Planetary Gears

Planetary gear sets, such as those found in automatic transmissions, provide the different gear ratios needed to propel a vehicle in the desired direction at the correct speed.

Gear teeth remain in constant mesh, which allows gear changes to be made without engaging or disengaging the gears, as is required in a manual transmission.

Instead, clutches and bands are used to either hold or release different members of the gear set to get the proper direction of rotation and gear ratio.

Helical Gears

Helical gears differ from spur gears in that their teeth are not parallel to the shaft axis; they are cut in a helix or angle around the gear axis. During rotation, parts of several teeth may be in mesh at the same time, reducing some of the loading characteristics of the standard spur gear.

However, this style of gearing can produce thrust forces parallel to the axis of the gear shaft. To minimize the effects, two helical gears with teeth opposite each other are used, which helps cancel the thrust during operation.

Herringbone Gears

Herringbone gears are an improvement over the double helical gear design. Both right- and left-hand cuts are used on the same gear blank, canceling out any thrust forces. Herringbone gears are capable of transmitting large amounts of horsepower and are frequently used in power transmission systems.

Gear Design Dictates Gear Oil Design

Differences in gear design create the need for significantly different lubricant formulations.

For instance, hypoid gears normally found in automotive differentials require GL-5 concentration and the performance of extreme-pressure additives due to their spiral sliding action.

Most manual transmissions have helical gears that do not require GL-5 performance. The helical gear is almost a straight-cut gear, but on an angle. There is spiral action and very little sliding action, and there is less need for extreme-pressure additives. GL-4 gear lubes provide less extreme-pressure additives than GL-5 lubes.

AMSOIL Gear Oil Recommendations

When comparing gear oil vs. engine oil, there are a number of differences between formulations. That’s why it is important to always use the correct oil for the correct application.

AMSOIL offers premium synthetic drivetrain lubricants to meet the needs of nearly every application. Check out our Product Guide to find what you need

Why Do I Need To Change My Oil?

What Happens to oil Making Me Needing to Change It?

Regardless of its quality, every motor oil eventually loses its potency and must be changed to ensure peak engine protection. Let’s take a look at what happens to motor oil over time and why you periodically need to change oil.

Losing the base

Base oils are the backbone of the finished lubricant that ends up in your engine. Over time, they lose effectiveness due to the following factors:


The interaction between oxygen molecules and motor oil molecules naturally leads to chemical breakdown.

Just as oxygen causes a cut apple to brown or exposed metal to rust, it breaks down base oils and reduces motor oil’s effectiveness.

Oxidation can lead to increased oil viscosity, which negatively affects energy efficiency. It also causes the formation of harmful deposits and sludge.

High heat

Today’s engines run hotter than ever before, with temperatures up to 235°F (113ºC), and even higher if towing or hauling.

The rate of oxidation for oil doubles for every 18°F (10°C) increase in temperature.


Your vehicle is subjected to temperature swings, even when it is parked in the garage.

Those temperature swings cause condensation to form inside your engine, leading to water contamination.

Leaving a vehicle parked for extended periods or taking short trips that don’t allow the engine to fully warm up allow water to remain in the oil rather than evaporating and exiting through the tailpipe. Water can lead to formation of sludge…yet another reason why you must change oil.

Viscosity is a motor oil’s most important property. The lower the viscosity, the faster the oils flows, like water. Thicker oils flow more slowly, like honey.

Viscosity loss

A lubricant’s viscosity is its most important property.

Viscosity has a direct bearing on wear protection, and your engine is designed to operate best using a motor oil of a specific viscosity (e.g. 5W-30).

The intense pressure the oil bears as it’s squeezed between moving parts, like the piston ring/cylinder wall interface, can tear apart, or shear, its molecular structure, leading to viscosity loss.

Suddenly, the 5W-30 motor oil your engine was designed to use is now essentially a 5W-20 oil, and wear protection may be compromised. When this happens, it’s time to change your oil.

Fuel dilution

Fuel can wash past the piston rings and contaminate the motor oil, causing it to lose viscosity.

Frequent short trips that don’t allow the oil to reach normal operating temperature can be especially problematic because the fuel won’t volatilize and exit through the PCV system.

Excessive fuel dilution leads to sludge and varnish, requiring you to change oil more frequently.

Additives: Additives are added to base oils to reduce destructive processes and enhance beneficial properties.

For example, antioxidant additives help slow the rate of oxidation. Detergency additives help prevent deposits and sludge while cleaning pre-existing deposits. Formulators add anti-wear additives to some lubricants to form a sacrificial barrier on metal components and help prevent wear.

Since they’re sacrificial in nature, additive depletion is one of the primary reasons motor oil loses its effectiveness and must be changed. 

While AMSOIL synthetic motor oil gives you the convenience of fitting oil changes into your schedule, it remains vital to install fresh oil at the appropriate time.