AMSOIL Premium Protection
10w40 and 20w50 Synthetic Motor Oils
High Viscosity Oil for RVs, Classic Cars and Older Vehicles —
Ideal for High Mileage Cars
High Zinc and Phosphorus ZDDP Motor Oil
for Engines
with
Flat Tappet Cams
Motor Oil
Diesel Oil
Natural Gas Engine Oil
Racing and
High Performance Oil
Motorcycle Oil
4 Stroke Oil
2 Cycle Oil
Engine Assembly Lubes
Suspension Fluid
Gear Oil
Grease
Transmission Fluid
Brake Fluid
Power Steering Fluid
Antifreeze
Bar and Chain Oil
Compressor Oil
Hydraulic Oil
Coolant Additive
Oil Analysis
Oil Filters
Air Filters
Metal Protectors
Engine Cleaners
Fuel Additives
Car Care Products
Other Car Products
AMSOIL Clothing, etc.

AMSOIL Premium Protection 10w40 and 20w50 Synthetic Motor Oils are specially formulated for use in both gasoline and diesel engines, offering multi-functionality and excellent wear protection. They are ideal for applications where the extra protection of a high viscosity oil is desired, such as in RVs, older cars and other classic vehicles, as well as most types of modern equipment. Also compatible for use in motorcycles. They are the ideal oil for high-mileage cars, vehicles with flat tappet cams and high-stress vehicles subject to hot temperatures, heavy hauling, trailer pulling or off-road use.
AMSOIL Premium Protection 10w40 and 20w50 Synthetic Motor Oils contain high levels of zinc and phosphorus (ZDDP), providing the extra anti-wear protection required by engines with flat-tappet cams and high-tension valve springs. They resist oxidation, neutralize acids, inhibit corrosion and protect against engine deposits, offering performance beyond conventional oil for convenience and trouble-free operation. Their superior high TBN (12+) synthetic formulation provides extended oil change intervals and maximum protection against engine wear.
- High viscosity oil
- High ZDDP motor oil — contains high levels of zinc and phosphorus
- Resists engine deposit formation
- Reduces engine wear
- Superior high temperature oil
- Excellent cold temperature oil for faster, easier cold-weather starts
- Retains its viscosity for longer oil change intervals
- High TBN (12+) ensures lasting protection against acid and soot
- Product Code/Price
- Product Details
- Shipping Info/Return Policy
| AMSOIL Premium Protection 10w40 Synthetic Motor Oil | |
|---|---|
Product Code |
Pkg./Size |
| AMOQT-EA | Quart Bottle |
| AMOQT-CA | Quart Bottles (case of 12) |
| AMO1G-EA | Gallon Bottle |
| AMO1G-CA | Gallon Bottles (case of 4) |
| AMOTP-EA | 2.5-Gallon Bottle |
| AMOTP-CA | 2.5-Gallon Bottle (case of 2) |
| AMO30-EA | 30-Gallon Drum |
| AMO55-EA | 55-Gallon Drum |
| Wholesale prices available for retail and commercial accounts. Please call 1-877-331-4642 or e-mail info@superoilcentral.com for more information. |
|
| AMSOIL Premium Protection 20w50 Synthetic Motor Oil | |
|---|---|
Product Code |
Pkg./Size |
| AROQT-EA | Quart Bottle |
| AROQT-CA | Quart Bottles (case of 12) |
| ARO1G-EA | Gallon Bottle |
| ARO1G-CA | Gallon Bottles (case of 4) |
| ARO16-EA | 16-Gallon Keg |
| ARO30-EA | 30-Gallon Drum |
| ARO55-EA | 55-Gallon Drum |
| ARO27-EA | 275-Gallon Tote |
| Wholesale prices available for retail and commercial accounts. Please call 1-877-331-4642 or e-mail info@superoilcentral.com for more information. |
|
Superior Oil for Severe Driving Conditions and High-Mileage Cars
AMSOIL Premium Protection 10w40 and 20w50 Synthetic Motor Oils are specially formulated to provide superior protection and performance in a wide variety of demanding applications. By incorporating high-quality synthetic base stocks and a superior high-zinc additive package, AMSOIL Premium Protection Synthetic Oils exceed the needs of large and small gasoline and diesel engines in cars, trucks, motorcycles, RVs, hot rods, marine, maintenance equipment and heavy equipment. They are the ideal oil for high-mileage cars, vehicles with flat tappet cams and high-stress vehicles subject to hot temperatures, heavy hauling, trailer pulling or off-road use.
High Zinc and Phosphorous ZDDP Motor Oil for Flat Tappet Camshaft Engines
To preserve catalytic converter life in newer vehicles, phosphorus levels in motor oil have been reduced. Concerns have risen that oils containing lower levels of zinc and phosphorus could provide insufficient protection in high-pressure areas of flat tappets and camshaft lobes found in many older and high-performance engines. Flat tappet camshafts undergo extreme pressure and loads, thus requiring an engine oil that is fortified with anti-wear additives to provide premium protection. The severity of higher spring pressure in racing engines also creates the need for additional wear protection.
The most commonly used anti-wear additive in motor oils is zinc dialkyldithiophosphate, or ZDDP. ZDDP contains both zinc and phosphorus components working together to provide anti-wear protection, and is most important during cam break-in procedures. Proper break-in oils should be used during the break-in phase for all new or rebuilt engines with flat tappets. These lubes provide the extra protection required to reduce wear at the point of contact during break-in and help the flat tappet face properly mate with the cam lobe. Once the break-in phase is completed, AMSOIL motor oils, which are formulated with high levels of zinc and phosphorus, will provide premium protection to flat tappet cams.
All engines, especially high-performance modified engines, benefit from oils with superior film strength and anti-wear properties. The flat tappet-camshaft lobe interface is the one area in an engine that has extreme contact load. Since this load increases significantly when non-stock, high-pressure valve springs are employed, the use of properly formulated motor oils is extremely important to reduce wear and extend flat tappet-camshaft life. For best protection, AMSOIL recommends motor oils containing high levels of zinc and phosphorus. The Flat Tappet and Camshaft Lobe Lubrication Bulletin (54 KB pdf) lists which AMSOIL synthetic motor oils contain high levels of zinc and phosphorus and their amounts.
High Viscosity Oil for Long Engine Life
AMSOIL Premium Protection 10w40 and 20w50 Synthetic Motor Oils are high viscosity oils engineered to protect against metal-to-metal contact. They resists viscosity shear and are formulated with a heavy treatment of zinc and other anti-wear additives for excellent protection of gears, bearings, cam lobes and other high-pressure components in engines and transmissions. AMSOIL Premium Protection Synthetic Motor Oils help extend engine life.
Wet Clutch Oil
AMSOIL Premium Protection 10w40 and 20w50 Synthetic Motor Oils exceed the requirements of wet clutch transmissions and reduce clutch wear for extended transmission life. They contain no friction modifiers, making them ideal for motorcycles, maintenance equipment and other wet clutch transmission applications. Formulated to prevent clutch glazing and slippage, AMSOIL Premium Protection Synthetic Motor Oils help insure smooth clutch engagement and long term, dependable transmission operation.
High Temperature Oil
The superior high-temperature protection of AMSOIL Premium Protection 10w40 and 20w50 Synthetic Motor Oils ensures the formation of a clean, protective film of oil between working parts during high-temperature, high-stress operation. Conventional oils tend to "boil off" (vaporize) in high temperature. Vaporized oils circulate poorly, reduce fuel efficiency and contribute to excessive emissions and engine wear. AMSOIL Premium Protection 10w40 and 20w50 Synthetic Motor Oils resist vaporization — in the NOACK Volatility Test, which measures the weight loss of an oil due to evaporation, they lose only 6.7 percent and 6.5 percent of their weight, respectively, in high-temperature service, surpassing rigorous European standards set at 13 percent weight loss!
With AMSOIL Premium Protection Synthetic Motor Oils, volatilization (burn-off), oxidation and excessive deposit formation from high heat are greatly reduced. Viscosity thickening is controlled and engines run cleaner, promoting cooler operation and long engine life in air- or liquid-cooled engines. In addition, the higher viscosity nature of AMSOIL Premium Protection Synthetic Motor Oils may help reduce motor oil consumption in equipment that experiences higher-than-normal usage rates when lower-viscosity lubricants are installed.
Cold Weather Oil
During sub-zero temperatures, AMSOIL Premium Protection 10w40 and 20w50 Synthetic Motor Oils flow to all parts of the engine much quicker than conventional oils, significantly reducing the rate of wear and increasing engine life. In the Pour Point Test, which determines the lowest temperature at which an oil flows, AMSOIL Premium Protection 10w40 and 20w50 Synthetic Motor Oils remain fluid at temperatures as low as -44°F and -33°F, respectively. Their outstanding low-temperature fluidity ensures easy cranking, quick, dependable cold-weather starts and fast lubrication.
High TBN Controls Engine Deposits
AMSOIL Premium Protection 10w40 and 20w50 Synthetic Motor Oils contain a superior detergent/dispersant additive package that, when tested after tens of thousands of miles of use in the crankcase, exhibited outstanding deposit control. This robust dispersant/detergent additive package makes them ideal for use in high-stress diesel engines — their high TBN (12+ Total Base Number) ensures lasting protection against acid and soot for their entire service life.
Protects Against Rust and Corrosion
AMSOIL Premium Protection 10w40 and 20w50 Synthetic Motor Oils contains special rust and corrosion inhibitors to protect iron parts, as well as copper, lead and aluminum bearing materials.
Extended Oil Change Intervals in Gasoline and Diesel Engines
The superior AMSOIL synthetic base stock and additive technology in AMSOIL Premium Protection 10w40 and 20w50 Synthetic Motor Oils exceed the requirements of both gasoline and diesel engines. AMSOIL Premium Protection Motor Oils neutralize acids, disperse soot and last longer in service than conventional oils.
AMSOIL Premium Protection 10w40 and 20w50 Synthetic Motor Oils are recommended for extended oil change intervals in unmodified, mechanically sound vehicles or equipment as follows:
Diesel Engines:
Normal Service: Up to 25,000 miles or one year, whichever comes first, or longer based on oil analysis*.
Severe Service: Up to 15,000 miles or one year, whichever comes first, or longer based on oil analysis*.
Gasoline Engines:
Normal and Severe Service: Up to 15,000 miles or one year, whichever comes first, or longer based on oil analysis*.
Motorcycles, Small Engines, Stationary Engines, Heavy Equipment and Other Applications:
Extend drain intervals based on oil analysis* or follow the manufacturer-recommended drain interval.
*Oil Analyzers, Inc., a division of AMSOIL, provides cost-effective, quality oil analysis services.
Definitions:
Modified Engines — Examples include the use of performance computer chips; non-OEM approved exhaust, fuel or air induction systems; and the use of fuels other than those recommended for normal operation by the manufacturers. Engines operating under modified conditions are excluded from extended drain recommendations.
Mechanically Sound Engines — Engines in good working condition and within the factory design settings. Mechanically sound engines, for example, do not leak oil or consume excessive amounts, are not worn out, do not overheat, do not have internal or external anti-freeze leaks and have properly working emission control systems. AMSOIL recommends repairing malfunctioning engines prior to the installation of AMSOIL synthetic oils.
Normal Service — Personal transportation vehicles frequently traveling greater than 10 miles (16 km) at a time and not operating under severe service.
Severe Service — Turbo/supercharged vehicles, commercial or fleet vehicles, excessive engine idling, use of AMSOIL engine oil in vehicles with over 100,000 miles without prior regular use of AMSOIL engine oil, daily short trip driving (less than 10 miles), frequent towing, plowing, hauling or dusty-condition driving.
Oil Filter Service Intervals
Extended oil drain intervals are based on the user following AMSOIL recommended oil filter service intervals:
- If using an AMSOIL Ea Oil Filters, install a new oil filter at time of oil change. AMSOIL Ea Oil Filters are designed for extended oil drain intervals. They stop smaller particles, allow more oil flow and last longer than regular filters.
- If using other brands of oil filters, install a new oil filter at time of oil change then change at the engine manufacturer's recommended filter change intervals.
Good to Know
- For best results, use AMSOIL Engine and Transmission Flush before installing AMSOIL synthetic motor oil.
- For maximum engine protection, use an AMSOIL Ea Oil Filter and an AMSOIL Ea Air Filter.
- AMSOIL recommends checking the oil at a minimum of every 3,000 miles to maintain proper fill levels and maximum engine protection.
- Oil Analyzers, Inc., a division of AMSOIL, Inc., provides cost effective, quality oil analysis services.
- Most quick lube service centers will install these products upon request or install them yourself.
Applications
AMSOIL Premium Protection 10w40 and 20w50 Synthetic Motor Oils are a multi-use, premium synthetic lubricant for applications that require or benefit from a higher viscosity oil. They are recommended for use in air- and liquid-cooled, large and small gasoline engines, transmissions and chain case applications, including those under warranty, that require the use of SAE 10w40 or SAE 20w50 motor oil. They are recommended for applications requiring the worldwide performance specifications listed on the AMSOIL Corporate website (see "Engine Protection Requirements" below).
Engine Protection Requirements
AMSOIL Synthetic Motor Oils meet or exceed specific API, ACEA and ILSAC service classifications and the engine protection requirements of various domestic and foreign engine manufacturers. Please visit the AMSOIL Corporate website for an up-to-date listing on AMSOIL 10w40 Synthetic Motor Oil or AMSOIL 20w50 Synthetic Motor Oil.
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