Amsoil Synthetic oil, the First in Synthetics since 1972

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Amsoil Frequently Asked Questions


How can I purchase AMSOIL products?

Answer: All you need to do is 'drill down' to the AMSOIL product you wish to purchase using the menu across the top of every page and down the right hand side. Every product has a direct buy link. If you have a question you can ask AMSOIL technical service via email, or ask me,
If you use more than a case of Amsoil a year you can save yourself money by becoming an AMSOIL Preferred Customer. You will save approximately 20 to 25 percent off the minumum suggested retail price.

How long have AMSOIL lubricants been on the market?
Answer: AMSOIL products have been available since 1972. AMSOIL 10W-40 Motor Oil was the first synthetic motor oil to meet American Petroleum Institute (API) service requirements. Today, AMSOIL manufactures synthetic lubricants for virtually all automotive, power sports, commercial and industrial applications.

Becoming an AMSOIL Dealer

Are AMSOIL Dealers required to sell products?
Answer: No. Dealers only need to sell if they want to earn commissions and bonuses. Even then, Dealers are encouraged to operate their businesses according to their own goals and schedules; AMSOIL does not place any pressure on its Dealers to make sales.

After becoming an AMSOIL Dealer, what business start-up costs might I expect?
Answer: New Dealers are not required to make any additional purchases beyond the cost of their annual Dealer registration. However, AMSOIL recommends new Dealers purchase the Literature Kit (G1312, G8312 Can.) and/or the Business Manual (G700, G8700 Can). The Literature Kit contains product data bulletins, price lists, application brochures and other documents that provide the information needed to begin selling AMSOIL products. The Business Manual contains material that helps new Dealers learn how to sell AMSOIL products, including manuals explaining how to administer the catalog program, the commercial program and the other programs through which AMSOIL is sold. It also contains information explaining how commissions are calculated and other material that helps Dealers run an AMSOIL business. Most of the information included in the Literature Kit and Business Manual is available free in the Dealer Zone.

AMSOIL also recommends Dealers purchase business cards; many also decide to purchase a name badge, a website, product catalogs and other literature items for distribution in their first year of business. Total costs vary depending on quantities, but can easily be kept below $200. Costs of this kind are common to all new business ventures and not exclusive to becoming an AMSOIL Dealer.

Is it possible to earn a residual income as an AMSOIL Dealer?
Answer: Residual income refers to money earned through indirect involvement. While it is possible to earn residual income as an AMSOIL Dealer, it requires an active group of successful downline Dealers. Dealers who register other Dealers and help train them to succeed can continue earning commissions if they fall ill or cannot actively work their Dealerships for another reason. Building a successful personal group, however, requires a strong commitment to education and training.

Do Dealers purchase AMSOIL products at artificially high prices through the multi-level-marketing program?
Answer: No. Dealers and Preferred Customers purchase AMSOIL products at wholesale pricing.

Are there costs required to cancel an AMSOIL Dealership?
Answer: No. The AMSOIL registration fee is refundable if notification of intent is made to the sponsor or AMSOIL INC. within three days of the date shown on the application. Otherwise, a Dealer can simply choose not to renew his or her membership.

Synthetic Oil Basics and Switching From Petroleum to Synthetic

What is the difference between synthetic and conventional oil?
Answer: Oil, whether synthetic or petroleum-based, consists of molecular chains of hydrogen and carbon atoms, referred to as hydrocarbons. Petroleum crude oil is a thick, highly flammable dark-brown or greenish liquid with high energy densities. Many contaminating elements exist in this complex mixture of hydrocarbons, including sulfur, nitrogen, oxygen and metal components such as nickel or vanadium. Petroleum crude oil is the raw material used for a wide variety of petrochemicals, including solvents, fertilizers, plastics and lubricants.

The oil refining process separates the various types of molecules in the oil by weight, resulting in a concentrated batch suitable for today’s uses such as gasoline, LPG, kerosene or base oils for lubricants. The chemical composition of conventional motor oil can vary substantially and depends on the raw crude oil refining process.

While petroleum base oils are refined, synthetic base oils are manufactured and can achieve a higher performance level. Synthetic oil is chemically engineered for a certain molecular composition with a tailored and uniform structure. Such fine-tuned control over the final molecular composition of synthetic oils is the key to the superior performance properties of these fluids. Designing molecular structures in a planned and orderly fashion results in molecules, and end-products, that are far more stable than their refined petroleum counterparts.

What roles do additives play in motor oil performance?
Answer: Most lubricating oils have other chemicals added to improve the overall performance of the fluid. Chemical additives are used to enhance the beneficial properties of the base oil or to make up for oil deficiencies. For passenger car motor oils, base oil makes up 70 percent to 80 percent of the final product; the other 20 percent to 30 percent is comprised of additive chemistry.

Additives help lubricants stand up to extreme operating environments. Even the best base oil would not be able to protect as well against the effects of heat, shearing forces, chemical and water dilution, corrosion and wear particles. In short, additives make good base oils even better. They give good base oils the performance benefits consumers have come to expect, such as multi-grade performance, extended drain intervals and extreme-pressure performance.

Anti-wear Agents chemically react to form a film barrier that prevents metal-to-metal contact and wear.

Antioxidants reduce the tendency for oil to react with oxygen and reduce sludge buildup.

Dispersants help to suspend and disperse contaminants in the oil to keep engine surfaces free of sludge and deposits. They fight the build-up of corrosive acids and are most efficient at controlling low-temperature deposits.

Visualization of Dispersants in operation
Detergents help to suspend and disperse contaminants in the oil to keep engine surfaces free of sludge and deposits. They are most efficient at controlling high-temperature deposits.

Extreme-Pressure Additives coat metal surfaces to prevent close-contact components from seizing under extreme pressure. They are activated by high temperatures and high loads to react with the metal’s surface to form a sacrificial wear layer on components.

Foam Inhibitors reduce the surface tension of air bubbles and causes them to collapse.

Foam Inhibitor Visualization
Friction Modifiers can be used to give oil more ‘slippery’ characteristics. In engine oils, friction modifiers are used to increase the oil’s lubricity for the purpose of reducing friction and improving fuel economy.

Pour Point Depressants give high-viscosity oils good low-temperature properties. Pour point depressant polymers inhibit the formation of crystals to minimize low-temperature viscosity increase.

Rust & Corrosion Inhibitors form a protective barrier over component surfaces to seal out water and contaminants. While most rust and corrosion inhibitors work by forming a physical barrier, some rust inhibitors function by neutralizing acids.

Viscosity Index Improvers are long-chain polymers that help control the viscosity of multi-grade engine oils. They expand and contract as temperatures vary. High temperatures cause VI improvers to expand and reduce oil thinning; low temperatures cause the VI improvers to contract and have little impact on oil viscosity.

Viscosity Index Improvers visualization

Can synthetic oil be used in new engines?
Answer: Yes. Synthetic oil is perfectly safe for use in new or high-mileage engines.

Must new cars be broken in using petroleum oil?
Answer: No. AMSOIL Synthetic motor oils can be safely used during break-in. In fact, many vehicles, including the Dodge Viper and Chevrolet Corvette, are factory-filled with synthetic oil.

Why is there a miles and time limit with respect to oil change intervals?
Answer: No matter how well motor oil is formulated, it won’t last forever. Motor oil marketers and vehicle manufacturers have developed general recommendations for the maximum amount of time or miles that the oil can be used; typically these intervals fall between 3,000 and 7,500 miles, depending on the type of service.

Many AMSOIL motor oils are specially formulated for extended drain intervals and provide maximum protection longer than other oils. Check the product data sheet for specific recommendations.

Will synthetic motor oils cause engines to leak oil?
Answer: No. Synthetic oils do not cause engines to leak oil. In fact, AMSOIL motor oil is fully compatible with modern seal materials and is properly formulated to condition seals, keeping them pliable to prevent leakage.

Can AMSOIL motor oils be mixed with other brands?
Answer: Yes. AMSOIL motor oils can be mixed with other motor oil brands; however, mixing AMSOIL products with other brands may decrease the effectiveness of AMSOIL oils and compromise their extended drain capability. Mixing other oils with AMSOIL motor oils also may void the AMSOIL limited warranty.

What kind of base stocks does AMSOIL use? Are AMSOIL synthetic lubricants PAO-based?
Answer: AMSOIL maintains formulation details as proprietary and does not divulge specifics regarding the type of synthetic base stocks used in its synthetic lubricants.

AMSOIL developed the world’s first API-qualified synthetic motor oil in 1972 and has remained the leader in the synthetic lubricant industry by continually researching new technologies and demanding only the highest-quality raw materials. As the company moves forward with new technologies it is increasingly more important that this information remains proprietary. AMSOIL views synthetic base oils the same as it views additives, with each having its own set of unique properties. AMSOIL does not insist on a particular type of base stock, but insists on particular performance parameters.

AMSOIL chooses whichever synthetic base stock or combination of base stocks delivers the desired result and tailors its lubricants to be application-specific (gasoline, diesel, racing, transmission, gear, extended drain, extreme temperatures, etc.). At the end of the day, the type of base stock used to formulate the oil is inconsequential; the product’s performance is what matters.

Why are AMSOIL engine oils capable of extended drain intervals?
Answer: AMSOIL engine oils are formulated using premium synthetic base oils, and the highest-quality additives, that provide extended-drain capabilities. Formulated with high-quality additives, AMSOIL engine oils achieve greater cleaning powers, while providing better equipment protection over longer oil drain intervals.

The unique synthetic formulation and robust TBN retention of AMSOIL synthetic engine oils work to resist oxidation and neutralize the acids that shorten the service life of other oils. Its characteristic resistance to high temperature volatility (burn-off) helps reduce oil consumption, while maintaining viscosity over longer periods of time than other oils. Please check the product data sheet for specific recommendations.

Will AMSOIL motor oils decrease oil consumption?
Answer: AMSOIL motor oils can reduce oil consumption in mechanically sound engines. However, AMSOIL motor oils cannot fix engines that consume oil because of mechanical problems.

Is there a recommended procedure for changing to AMSOIL motor oil?
Answer: There are no special requirements for changing to AMSOIL motor oil. However, in older vehicles with high mileage, it may be advisable to use AMSOIL Engine Flush first. This will ensure the engine is clean and free of accumulated contaminants that may affect the service life of AMSOIL motor oil. Installation of an AMSOIL Absolute Efficiency Oil Filter (EaO) at every oil change is recommended.

How do AMSOIL motor oils compare to other motor oils?
Answer: The importance of good-quality oil in your engine cannot be overstated. AMSOIL synthetic motor oils consistently outperform conventional and other synthetic oils in virtually every category of performance, including wear protection, extreme high and low temperature performance, foam control, viscosity retention, rust and corrosion protection, volatility and fuel economy.

While other brands may have good performance in some of these areas, AMSOIL consistently performs at the top in every category. Drivers can have confidence knowing that AMSOIL motor oils provide maximum performance and protection.

What are “normal” and “severe” driving conditions?
Answer: Each vehicle manufacturer defines “normal” and “severe” driving conditions for their equipment; AMSOIL recommends owners check these definitions in their owner’s manual to determine the service condition in which they typically drive.

AMSOIL defines normal service as personal vehicles frequently traveling greater than 10 miles at a time and not operating under severe service.

AMSOIL defines severe service for gasoline engines as turbo/supercharge engines, commercial or fleet vehicles, excessive engine idling, use of AMSOIL engine oil in vehicles with more than 100,000 miles without prior regular use of AMSOIL engine oil, daily short-trip driving less than 10 miles (16km), frequent towing, plowing, hauling or dusty-condition driving.

AMSOIL defines severe service for diesel engines as extensive engine idling, daily short-trip driving less than 10 miles (16km) or frequent dusty-condition driving.

See the AMSOIL Product Recommendation and Drain Interval Chart>, publication number G1490, for additional information.

I am considering replacing the petroleum oil with AMSOIL synthetic oil in an engine that has 50,000 miles on it. I have heard that synthetics might clean the engine and cause plugging of the oil filter and passageways. Is this true?
Answer: Absolutely not. Switching from petroleum oil to AMSOIL in routinely maintained vehicles will not cause clogged oil filters or passageways, regardless of mileage. Sludge, which is caused by poor quality oil and neglected maintenance practices, would have to be present in significant amounts to plug oil filters and passageways. If this excessive amount of sludge is present in an engine, it is just a matter of time before oil filters and passageways clog, regardless of the installation of AMSOIL.

Motor Oil: Gasoline Auto and Light Truck

Are AMSOIL motor oils “all-season” oils?
Answer: Yes. Because AMSOIL motor oils are formulated with premium synthetic base oils, they have superior high and low-temperature performance. Synthetic oils resist thinning out at high temperatures to maintain critical protection in extreme heat. They also minimize sludge and deposit formation in high-temperature operation. AMSOIL synthetic motor oils resist thickening in cold temperatures to provide rapid cold starts and improved low-temperature operation compared to conventional oils.

Why are there multiple oils of the same viscosity?
Answer: A significant portion of an oils performance and specification compatibility comes from the additive components blended in the oil. AMSOIL offers multiple oils with the same viscosity because they are formulated with different additive packages that carry different manufacturer oil specifications. This allows AMSOIL to provide premium oil for more equipment manufacturers and industry specifications than would be possible if only a single viscosity grade was offered.

What is the difference between AMSOIL XL Series Motor Oils and other AMSOIL motor oils?
Answer: AMSOIL XL Series Motor Oils have a recommended oil drain interval of 10,000 miles or 6 months, whichever comes first. AMSOIL top-tier motor oils carry a drain interval of 25,000 miles or 1 year, whichever comes first. AMSOIL top-tier motor oils incorporate better base-oils and have more robust additives, which allow for longer extended drains than AMSOIL XL Series Motor Oils.

Why aren’t AMSOIL racing oils recommended for street-driven vehicles?
Answer: AMSOIL Dominator Racing Oils are premium quality oils formulated for maximum protection in high-performance and racing applications. Dominator Racing Oils are fortified with high levels of zinc and phosphorus, which are incompatible with catalytic converters common in today’s street-driven vehicles; therefore, they do not carry API service classifications required by many standard passenger vehicles. However, AMSOIL Racing Oils are the ideal recommendation for street rods, muscle cars and other high performance vehicles driven on the street.

What does the “W” represent in 5W-30 motor oil?
Answer: The “W” in 5W-30 motor oil stands for “winter” and represents that the oil meets or exceeds certain criteria for good low-temperature performance. Oil with SAE viscosity grade 5W-30 will behave like an SAE 30 oil at high temperatures and SAE 5W oil at low temperatures, providing the necessary fluidity for rapid starts and efficient engine operation at low temperatures.

What is considered to be “normal” oil consumption?
Answer: What may be normal oil consumption for one vehicle may be excessive for another. As a rule, the more miles and wear accumulated on an engine, the more oil that engine will consume. Typically, one quart of oil within 3,000 miles is normal, but you should confirm oil consumption limits with the vehicle manufacturer. The following document explains mechanical related issues that can lead to oil consumption: Engine Oil Consumption

Motor Oil: Heavy Duty & Off-Road Diesel

Is it safe to use Engine Flush in diesel engines?
Answer: Yes. AMSOIL Engine Flush (AEF) is safe to use in gasoline and diesel engines. This multi-use formulation helps loosen sticky valves and piston rings. It also helps reduce lifter noise and removes sludge and deposit buildup for clean operation and lower operating temperatures.

Can diesel oils be used in gasoline engines?
Answer: It depends; some AMSOIL diesel oils carry gasoline specifications. Check the product data bulletin for specific product and drain interval recommendations.

Does AMSOIL offer diesel oils for equipment calling for the CJ-4 specification?
Answer: Yes. The CJ-4 specification is for 2007 and later high-speed, four-stroke diesel engines. AMSOIL 5W-40 Premium API CJ-4 Synthetic Diesel Oil (DEO) and AMSOIL 15W-40 Premium API CJ-4 Synthetic Diesel Oil (DME) are formulated to meet the sulfur content requirements necessary to be compatible with exhaust aftertreatment systems and/or extended drain intervals.

Are the AMSOIL CJ-4 diesel oils okay to use in older diesel engines?
Answer: Yes. AMSOIL CJ-4 oils are formulated with lower sulfur content to be compatible with 2006 and later high-speed, four-stroke diesel engines with exhaust aftertreatment systems and/or extended drain intervals. AMSOIL 5W-40 CJ-4 Synthetic Diesel Oil and 15W-40 CJ-4 Synthetic Diesel Oil exceed previous diesel oil specifications, meaning they are suitable for use in older diesel engines. CJ-4 oils exceed performance criteria for CI-4 Plus, CI-4, CH-4, CG-4 and CF-4 and can be safely used in place of those oils.

What is the difference between AMSOIL 5W-40 and 15W-40 diesel oil?
Answer: Both AMSOIL 5W-40 and 15W-40 diesel oils are multi-grade oils, meaning they have good performance in high and low temperatures. AMSOIL 5W-40 and 15W-40 will both behave like SAE 40 grade oils in high temperatures; however, the 5W-40 will be thinner than the 15W-40 at cold temperatures.

Can CI-4 rated oil be used in 2007 or newer diesel engines?
Answer: Model 2007 and newer diesel engines are fitted with exhaust aftertreatment systems necessary to meet current minimum emissions requirements and are sensitive to the sulfur content of the oil. CI-4 and CI-4 Plus oils typically contain too much sulfated ash to be compatible with these aftertreatment systems.

As always, when in doubt, check the specification of the oil to determine the suitability of the oil for your intended application. AMSOIL INC. recommends following the manufacturer recommendations specific to the diesel oil rating called for in the specific model/year vehicle.

Motor Oil: Power Sports and Small Engine

What is the actual oil weight for the following suspension fluids: STL - Shock Therapy Light and STM - Shock Therapy Medium?
Answer: Shock Therapy Light corresponds to a 5 wt. and Shock Therapy Medium corresponds to a 10 wt.

Is it safe to use 10W-30 in a small engine that calls for SAE 30 petroleum motor oil?
Answer: Yes. During operation the 10W-30 motor oil will perform like SAE 30 motor oil, and it is safe to use in an application requiring straight SAE 30 oil. If starting the small engine in temperatures below 50°F, the multi-grade oil may improve starting.

Can AMSOIL Formula 4-Stroke® 0W-40 Synthetic Motor Oil be used in new four-stroke snowmobiles?
Answer: Yes. AMSOIL Formula 4-Stroke 0W-40 (AFF) is specifically formulated for use in small, hard working four-stroke engines. It is ideal for four-cycle snowmobiles, ATVs, personal watercraft, four-stroke boat motors, lawn equipment, etc.

Can AMSOIL Signature Series 0W-30 Synthetic Motor Oil be used in lawnmower applications?
Answer: Yes. AMSOIL Signature Series 0W-30 Synthetic Motor Oil (AZO) can be used in lawnmower applications calling for SAE 30 weight engine oil. However, due to its robust formulation specifically designed for hot temperature, severe service operation of small engines AMSOIL 4-Stroke 10W-30/SAE 30 Synthetic Small Engine Oil (ASE) is recommended.

Is it okay to break in new two-cycle equipment using AMSOIL synthetic motor oils?
Answer: Yes. There are no problems using AMSOIL 2-cycle oils for break-in periods.

What does “wet clutch” mean when discussing power sports equipment?
Answer: Wet clutches are immersed in motor oil to cool the clutch plates. Wet clutches are often found in motorcycle applications and they require fluids with certain frictional requirements to promote smooth shifting and clutch engagement. Dry clutches require no lubrication.

Does AMSOIL have a two-cycle engine oil recommended for power valves?
Answer: AMSOIL INTERCEPTOR™ Synthetic 2-Cycle Oil (AIT) is recommended for power valve applications. It has optimal detergency to keep power valves clean and provides superior anti-wear protection.

Will 100:1 mix ratios while using AMSOIL Saber Professional or AMSOIL Saber Outboard 2-cycle Oils void warranties?
Answer: Using AMSOIL Saber Professional (ATP) or AMSOIL Saber Outboard (ATO) at 100:1 mix ratios, where 50:1 is recommended by the manufacturer, will not void warranties. For more information, contact AMSOIL Technical Services at (715) 399-8324.

Can AMSOIL Formula 4-Stroke® 0W-40 Synthetic Motor Oil be used in a four-stroke ATV or snowmobile where the recommended viscosity is 5W-50?
Answer: Because AMSOIL builds an extremely shear-stable product, AMSOIL Formula 4-Stroke 0W-40 (AFF) can be used in place of SAE 50 oil in some cases. Contact AMSOIL Technical Services for specific product interchange information.

I have had some retailers tell me that your 100:1 Pre-mix 2-Cycle Oil will carbon the valves and make them stick. I started out using AMSOIL at 80:1 and have had trouble starting chain saws and weed whackers. An Echo dealer told me not to use AMSOIL or my warranty would be void. Do I need to reset the carburetor setting? As it is now the saw floods out and won't start until I turn it upside down and let it stand overnight. My Mac saws call for 40:1 and Echo is 50:1. Where do I go from here?
Answer:There should be no need to adjust the carburetor when using the synthetic two cycle oil. The use of AMSOIL in these applications does not void the warranty from the manufacturer. It appears, based on your description, that too much oil is being mixed with the gasoline loading up the engines. The best ratio with the AMSOIL would be 100:1. That will be the best ratio to insure good performance and that exhaust valves do not carbon up.

Is it okay to break in a new two-cycle chain saw engine using AMSOIL Synthetic 100:1 Pre-Mix 2-Cycle Oil, or should another oil be used?
Answer: It is not necessary to break in two-cycle engines with another oil. AMSOIL 2-Cycle Oils may be used immediately in new two-cycle engines.

Motor Oil: Motorcycles

What AMSOIL motor oils are recommended for Harley-Davidson motorcycles?
Answer: AMSOIL SAE 20W-50 Synthetic Motorcycle Oil (MCV) and Synthetic SAE 60 Motorcycle Oil (MCS) are the most commonly recommended oils for Harley applications. Check the AMSOIL Motorcycle Look-up Guide for specific questions.

What is the difference between Formula 4-Stroke® 10W-40 Synthetic Scooter Oil and SAE 10W-40 Synthetic Motorcycle Oil?
Answer: AMSOIL 10W-40 Synthetic Motor Oil (MCF) contains an additive package that is designed for the extreme pressures and high temperatures common in motorcycle applications. Its high TBN retention also makes it the appropriate choice for extended drain intervals. In scooter applications, AMSOIL 10W-40 Synthetic Scooter Oil (ASO) is the more economical choice.

What is the recommended transmission lubricant for a Harley Davidson Big Twin?
Answer: In newer Big Twins, AMSOIL recommends AMSOIL 20W-50 Synthetic Motorcycle Oil (MCV) or SEVERE GEAR® Synthetic Extreme Pressure Lubricant 75W-110 (SVT). In older Harleys, such as Knuckleheads, Panheads and Shovelheads, AMSOIL Synthetic SAE 60 Motorcycle Oil (MCS) is recommended.

What is the recommended transmission lubricant for a Harley-Davidson Sportster?
Answer: AMSOIL recommends 20W-50 Motorcycle Oil (MCV) for the Harley-Davidson Sportster.

Are AMSOIL motorcycle oils wet clutch compatible?
Answer: Yes. AMSOIL Motorcycle Oils meet JASO MA2 friction requirements for use in wet clutch applications.

Is AMSOIL Series 2000 Synthetic Chaincase Lubricant acceptable to use in the primary of a Harley Davidson Big Twin?
Answer: AMSOIL Series 2000 Synthetic Chaincase Lubricant (TCC) does not have the correct viscosity for use in Harley-Davidson primaries, and is not recommended for these applications. AMSOIL recommends a product such as AMSOIL Synthetic 20W-50 (MCV) Motorcycle oil for Harley-Davidson primaries.

How can AMSOIL recommend 20W-50 Synthetic Motorcycle Oil for use in the primary and transmission in certain motorcycles?
Answer: AMSOIL Motorcycle Oils are engineered with additive packages specifically designed to provide higher performance in motorcycle engines, transmissions and primaries.

What is the oil change interval for AMSOIL motorcycle oils?
Answer: AMSOIL motorcycle oils are engineered to provide protection up to twice the manufacturer’s recommended change interval or one year, whichever comes first.

For Big Twin Harley-Davidson transmissions, follow the Harley-Davidson recommended drain interval for synthetic oil up to 20,000 miles or one year, whichever comes first. Unless you are using an AMSOIL Ea air filter, change the filter based on the manufacturer’s recommended intervals.

Are AMSOIL motorcycle oils different from AMSOIL automotive oils?
Answer: Yes. In addition to withstanding extreme pressure, protecting against rust and withstanding high temperatures, motorcycle oils must be compatible with wet clutches. AMSOIL motorcycle oils are designed to meet the unique frictional requirements necessary for wet clutch compatibility and provide maximum protection and performance in these applications.

Why does AMSOIL offer more than one viscosity motorcycle oil?
Answer: AMSOIL offers motorcycle oils in different viscosities to accommodate the differences between motorcycle models and manufacturers. Just as in automotive applications, motorcycle engines require specific oil viscosities for optimal performance and protection based on the components and tolerances in the engine. Check the AMSOIL on-line look-up guide for specific recommendations.

Transmission Fluids

What are the change intervals for AMSOIL Synthetic Universal Automatic Transmission Fluid and AMSOIL Synthetic Fuel Efficient Automatic Transmission Fluid?
Answer: AMSOIL Synthetic Universal Automatic Transmission Fluid (ATF) and Synthetic Fuel Efficient Automatic Transmission Fluid (ATL) are recommended for use up to 50,000 miles in severe service operation and up to 100,000 miles in normal service operation, or per vehicle manufacturer recommendations, whichever is longer. Use vehicle manufacturer or transmission manufacturer definitions for normal and severe service, as these can vary among manufacturers. Check the AMSOIL on-line look-up guide for specific recommendations.

Is it required that all of the transmission fluid be removed before adding AMSOIL transmission fluid?
Answer: No. AMSOIL Synthetic Universal Automatic Transmission Fluid (ATF) and AMSOIL Synthetic Fuel Efficient Automatic Transmission Fluid (ATL) are compatible with petroleum and synthetic transmission fluids and can be used to top off transmission fluid levels. However, if conducting a transmission fluid change, most of the fluid in the automatic transmission will be replaced with the new fluid.

Can AMSOIL Engine and Transmission Flush be used in all transmissions?
Answer: AMSOIL Engine and Transmission Flush (FLSH) is safe to clean sludge and deposit buildup from automatic transmissions to promote efficient operation and fuel efficiency. AMSOIL Engine and Transmission Flush is not recommended for manual transmissions, CVT transmissions, transaxles or differentials. AMSOIL recommends that the transmission filter be changed when performing a flush.

Does AMSOIL offer transmission fluid for manual transmissions? If so, what is the change interval?
Answer: AMSOIL offers two manual transmission fluids: Synthetic Manual Synchromesh Transmission Fluid 5W-30 (MTF) and Synthetic Manual Transmission and Transaxle Gear Lube 75W-90 (MTG).

Manual Synchromesh Transmission Fluid 5W-30 (MTF) is engineered for 50,000 mile service intervals or longer (up to 150,000 miles) as indicated by the equipment manufacturer. Manual Transmission and Transaxle Gear Lube 75W-90 (MTG) is engineered to last two times longer than conventional petroleum GL-4 gear oils. Following equipment manufacturer drain intervals for synthetic oils is recommended. Check the AMSOIL on-line look-up guide for specific recommendations.

Is AMSOIL Engine and Transmission Flush compatible with seals?
Answer: Yes. AMSOIL Engine and Transmission Flush is compatible with engine and transmission seal materials. In fact, this product is specially formulated to condition seals to help prevent leaks and extend seal life.

Filters: Air and Oil

What is the difference between a “micron rating” and “beta ratio test” when referring to filters?
Answer: A filter’s micron rating refers to the smallest size contaminant the filter media can remove; however, there is no correlation between micron rating and a filter’s efficiency percentage.

The beta ratio test measures a filter’s efficiency for removing particles of a certain size by comparing the amount of contaminant particles before and after filtration. The number of particles after filtration is divided by the number before filtration. The resulting number is the beta ratio. AMSOIL Ea filters have a minimum beta ratio of 75, meaning they are capable of removing 98.7% of contaminant particles of a stated size.

Are AMSOIL air filters washable? How are they cleaned?
Answer: AMSOIL Ea Air Filters are not washable, but should be cleaned by vacuum or shop air every 25,000 miles or one year, whichever comes first. Clean the filter housing with a cloth, use care to avoid knocking contaminants into the air inlet.

To vacuum, carefully vacuum the filter media on the dirty side. If using shop air, blow the filter media at a 45-degree angle on the clean side, using low-pressure air (15 – 20 psi).

Is it okay to use non-AMSOIL brand filters with AMSOIL lubricants?
Answer: Yes. Non-AMSOIL brand filters may be used with AMSOIL lubricants. However, the manufacturer recommended change intervals and cleaning procedures should be followed. AMSOIL supports the full 10,000 mile/6 month XL Motor Oil drain interval with any non-AMSOIL oil filter.

What is the proper change interval for Ea® By-Pass Filters?
Answer: When used in conjunction with AMSOIL motor oil and an AMSOIL Ea or Donaldson® Endurance™ Full-Flow Oil Filter, Ea By-Pass Filters should be changed every other full-flow filter change up to 60,000 miles. When used with other brands of motor oil or full-flow filters, Ea By-Pass Filters should be changed every other full-flow filter change. AMSOIL recommends using oil analysis when extending oil drain intervals.

Can a larger size filter be used in place of what a vehicle calls for?
Answer: No. Filter recommendations by AMSOIL are based on specific equipment manufacturer requirements. Using a filter in an application it is not recommended for will void the filter’s limited AMSOIL warranty.

How long can oil drains be extended when using a by-pass filtration system?
Answer: AMSOIL By-Pass Filters are designed to filter out fine particles; they are not meant to extend oil change intervals beyond original recommendations. However, when fine particles are filtered out of the motor oil, it may be possible to attain longer drain intervals. This should be determined by used oil analysis. In addition, the use of an AMSOIL bypass system may allow for the use of larger oil filters, which can increase filtering capacity.

What is the service life of AMSOIL Ea® Air and Oil Filters?
Answer: AMSOIL Ea Air Filters are guaranteed for up to 100,000 miles/four years provided they are cleaned by vacuum or compressed air every 25,000 miles/one year.

When used in conjunction with an AMSOIL extended-drain motor oil, Ea filters designated with product code EaO are guaranteed for up to 25,000 miles/one year in normal service and up to 15,000 miles/one year in severe service. Ea filters designated with product code Ea15K are guaranteed for up to 15,000 miles/one year, whichever comes first, regardless of driving conditions. It is recommended that all AMSOIL-brand oil filters be changed when the motor oil is changed. If motor oil other than AMSOIL is used, AMSOIL Ea Oil Filters must be changed according to the vehicle manufacturer’s recommendations.

Fuel Additives: Gasoline

Can multiple AMSOIL gasoline fuel additives be mixed together with gasoline?
Answer: Yes. AMSOIL fuel additives are compatible. When selecting a fuel additive be sure that it is the appropriate choice for the application. For specific product recommendations, contact AMSOIL Technical Services at (715) 399-TECH (8324) or

What exactly does AMSOIL P.i.® gasoline fuel additive do?
Answer: For optimum fuel efficiency and lower emissions, fuel must first be atomized into a fine mist prior to entering the combustion chamber. Over time, injector deposits produce irregular spray patterns with heavy streams of gasoline that reduce performance, while intake valve deposits also decrease efficiency. AMSOIL P.i. (API) is a potent gasoline additive designed to clean combustion chamber deposits, intake valve deposits and port fuel injector deposits to improve fuel efficiency up to 5.7 percent and an average of 2.3 percent.

Does AMSOIL offer any fuel additives that combat ethanol-related problems?
Answer: Yes. AMSOIL Quickshot® (AQS) contains a revolutionary technology that focuses on three major fuel-related issues plaguing small engines and powersports equipment: ethanol, water and dirty pump gas.

Ethanol in fuel has a tendency to absorb water and separate from the gasoline. It then sinks to the bottom of the gas tank, where it quickly degrades and creates gum, varnish and other insoluble debris that can plug fuel flow passages and negatively affect engine performance. When this ethanol/water mixture is pulled into the engine, it creates a lean-burn situation that increases combustion chamber temperatures and can lead to engine damage. AMSOIL Quickshot is proven to successfully fight ethanol problems and improve operation.

How often should AMSOIL Gasoline Stabilizer be used in powersports and small engine equipment?
Answer: AMSOIL Gasoline Stabilizer (AST) should be used when fuel is stored for long-term, seasonal storage. For short- to medium-term storage, AMSOIL Quickshot® (AQS) is recommended.

Fuel Additives: Diesel

Does AMSOIL Diesel Concentrate comply with Ultra Low Diesel (ULSD) fuel requirements?
Answer: Yes. AMSOIL Diesel Concentrate (ADF) is compliant with the federal requirements for ULSD. AMSOIL Cetane Boost (ACB) and Cold Flow Improver (ACF) also meet USLD requirements.

Does AMSOIL Cold Flow Improver work if diesel fuel is beginning to gel?
Answer: AMSOIL Cold Flow Improver (ACF) is designed to prevent fuel from gelling and clogging fuel lines and filters. If the fuel is beginning to gel, the fuel should be treated with AMSOIL Diesel Recovery Emergency Fuel Treatment (DRC). Diesel Recovery disperses the wax crystals and allows the fuel to flow.

Is it safe to use AMSOIL Engine and Transmission Flush in diesel trucks and cars?
Answer: Yes. AMSOIL Engine and Transmission Flush (FLSH) is safe for use in diesel and gasoline engines and automatic transmissions to help restore equipment efficiency and operation. AMSOIL Engine and Transmission Flush is not recommended for manual transmission, CVT transmissions, differentials, transaxles, small engines or power sports equipment.

What benefits are seen when using AMSOIL Cetane Boost?
Answer: Elevated cetane levels, generally above 50, are preferable to get the most performance and power out of diesel engines. AMSOIL Cetane Boost (ACB) is engineered to improve the cetane value of diesel fuel up to seven points. AMSOIL Cetane Boost is appropriate for all types of service, including heavy- and light-duty service, on- and off- road and marine diesel engines. Cetane Boost is compatible with biodiesel and all types of exhaust emissions systems and is excellent for use with Ultra Low Sulfur Diesel Fuel (ULSD). AMSOIL Cetane Boost also improves operating cost by improving fuel economy, provides complete combustion for better power, reduces white smoke and emissions, and improves cold temperature starting.

Vehicle Warranty and AMSOIL

How does using AMSOIL synthetic motor oil affect new vehicle warranties?
Answer: Using AMSOIL synthetic motor oil has no affect on vehicle warranties. A federal law called the Magnuson-Moss Act (1975) prevents original equipment manufacturers from putting conditions on vehicle warranties attached to any product or service identified by brand, trade or corporate name, unless the manufacturer provides that product or service free of charge. This means consumers have the freedom to use aftermarket products of their choice without fear of losing the original limited or implied vehicle warranty. For additional information, contact the AMSOIL Technical Department at (715) 399-TECH (8324) or

Will extending oil change intervals void new vehicle warranties?
Answer: No. Extending oil change intervals will not void new vehicle warranties. To affect the vehicle warranty, it must be determined that the lubricant was directly responsible for the failure; if the oil didn’t cause the problem, the warranty cannot be voided, regardless of brand or length of time in use.

Does AMSOIL have a warranty for products?
Answer: Yes. AMSOIL provides a limited warranty on all AMSOIL lubricants and filters.

Where should questions, regarding warranty, be directed?
Answer: Call the AMSOIL Technical Department at (715) 399-TECH (8324) with questions or issues regarding warranties.


Is there a glossary of common lubricant terms used in technical bulletins?
Where can AMSOIL product recommendations, for equipment, be found?
Answer: AMSOIL provides a number of product lookup and filter lookup guides to help determine the appropriate lubricant or filter for an application. These lookup guides are found on the right-hand side navigation menu at The following lookup guides are available to determine proper recommendations: Auto and Light Truck, Power Sports, Small Engine, TRICO Heavy Duty, Vintage Vehicle and Heavy Duty.

Oil Analysis

What is oil analysis?
Answer: Oil analysis is a process for determining the chemical properties of a lubricant. It’s often used to detect mechanical issues before major failures occur. Used oil samples are analyzed for specific physical properties, contaminant levels and wear debris from the equipment to determine if the oil can remain in service. Oil analysis can also monitor the wear rate of the equipment and detect if wear is elevated beyond acceptable limits. It is often used as part of a preventative maintenance program.

Why should oil analysis be done?
Answer: As part of a preventative maintenance program, oil analysis can help owners and operators be proactive in their maintenance practices to help increase equipment productivity and eliminate costly downtime. The cost of routine oil analysis far outweighs the costs to replace major equipment on large industrial equipment, commercial and passenger car vehicles.

For those reluctant to extended oil intervals, oil analysis provides evidence that AMSOIL motor oils have exception performance and protection capabilities in extended service.

Does AMSOIL provide oil analysis services?
Answer: Yes. AMSOIL provides oil analysis services through Oil Analyzers Inc. Visit or call (877) 458-3315 for more information.

Maintenance Products

Is AMSOIL Propylene Glycol Antifreeze and Engine Coolant compatible with aluminum intakes, cylinder heads and engine blocks?
Answer: Yes. AMSOIL Antifreeze and Engine Coolant (ANT) is compatible with all engine and cooling system components. It surpasses all ASTM standards for metallic corrosion to protect metals and provide uncompromised cooling protection.

Does AMSOIL recommend a particular type of water when mixing AMSOIL Antifreeze and Engine Coolant?
Answer: AMSOIL recommends deionized or distilled water when mixing with AMSOIL Antifreeze and Engine Coolant (ANT). Using deionized or distilled water prevents adding harmful contaminants that can negatively affect the antifreeze product and cooling system equipment.

Is AMSOIL Antifreeze and Engine Coolant silicate and borate free?
Answer: Yes. AMSOIL Antifreeze and Engine Coolant (ANT) contains proprietary poly-organic acid technology that is silicate and borate free.

Gear Oils

Will GL-2 through GL-5 gear lubes hurt synchronizers?
Answer: No. All gear oils AMSOIL recommends for manual transmission applications are perfectly safe for synchronizer materials.

Does AMSOIL Slip Lock need to be used with AMSOIL gear lubricants?
Answer: AMSOIL automotive gear lubricants have excellent frictional properties and generally will not need to be fortified with additives. If on rare occasions differential chatter occurs, AMSOIL Slip Lock is recommended.
Can different AMSOIL gear lubricant viscosities be mixed?
Answer: AMSOIL gear lubricants are compatible with one another. Mixing different AMSOIL gear lubricants, however, could change the viscosity properties of the oils, depending on the ratios and viscosities mixed. This could impact the drain interval. Mixing different viscosities of lubricants should be minimized whenever possible.

If a vehicle manufacturer recommends a 75W-90 gear lube, may a 75W-140 be used?
Answer: No. In most cases, 75W-140 gear lube is too thick to be used in place of 75W-90. For modified or non-stock differentials where a higher viscosity gear lube may be desired, AMSOIL typically recommends 75W-110. Contact AMSOIL Technical Services for specific recommendations at (715) 399-TECH (8324) or

Are AMSOIL gear lubes safe for yellow metals?
Answer: Yes. As long as temperatures don’t exceed 250°F (121°C), all AMSOIL automotive gear oils are safe to use in drive train applications with yellow metals. Check the AMSOIL on-line look-up guide at for specific questions.

Is AMSOIL gear lube compatible with RTV sealant?
Answer: AMSOIL automotive gear lubricants are compatible with RTV sealant. It is very important the RTV sealant manufacturer’s instructions be followed and the product be FULLY cured before contact with the gear lubricant.

Can AMSOIL Severe Gear® be used in Harley-Davidson transmissions?
Answer: Yes. In Evolution 1340 and all Twin Cam Harley-Davidsons, AMSOIL recommends AMSOIL 20W-50 Synthetic Motorcycle Oil (MCV) or Severe Gear 75W-110 Synthetic EP Gear Lube (SVT). In older Harleys, such as Knuckleheads, Panheads and Shovelheads, AMSOIL Synthetic SAE 60 Motorcycle Oil (MCS) or Severe Gear 75W-140 Synthetic EP Gear Lube (SVO) is recommended.

Is AMSOIL gear lube compatible with conventional gear lubricants?
Answer: AMSOIL automotive gear lubricants are compatible with other synthetic and petroleum based gear lubricants. However, mixing AMSOIL gear oils with oils will shorten the life expectancy and reduce performance benefits.

Mercon Applications

Is AMSOIL Synthetic Automatic Transmission Fluid safe to use in Mercon V and Mercon applications?
Answer: Yes. AMSOIL Synthetic Automatic Transmission Fluid (ATF) is engineered to provide maximum performance and protection in a number of automatic transmission applications. AMSOIL Synthetic Automatic Transmission Fluid is formulated for Mercon V applications and is backward compatible, meaning it is also suitable for Mercon applications.

Can an “off the shelf”, singularly specified Ford Mercon product be used in a Mercon V application?
Answer: No. The Mercon specification precedes the Mercon V specification; therefore, it is not formulated to adequately protect and perform in Mercon V applications. AMSOIL Synthetic Automatic Transmission Fluid (ATF) is engineered to exceed Mercon V and Mercon specifications and can be used in both applications.

Torque-Drive® Synthetic Automatic Transmission Fluid is engineered to meet the Mercon specification and is not recommended for Mercon V applications.

Aggrand Natural Fertilizers Altrum Wellness Products WIX air, oil and racing filters Donaldson endurance and heavy-duty filters MANN Filters Oil Analyzers, Inc. Oil analysis services for automotive, fleet and industrial applications



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