AMSOIL Factory Direct Synthetic Lubricants




API Motor Oil Comparison Test Results - See who came out on Top

API Motor Oil Comparison Testing: Thinking all motor oil is the same? Think again!

AMSOIL Synthetic 10W-30 Motor Oil (ATM) and 10 competing conventional and synthetic 10W-30 motor oils were subjected to a series of API motor oil comparison tests. The competing oils included petroleum-based Castrol GTX Drive Hard, Mobil Drive Clean, Pennzoil with Purebase, Quaker State Peak Performance and Valvoline, as well as synthetic-based Valvoline Synpower, Quaker State, Castrol Syntec, Pennzoil and Mobil 1 SuperSyn Multi-Vehicle.

Seven API motor oil comparison tests were run on the motor oils. The Thin-Film Oxygen Uptake Test (TFOUT) measures the oxidation stability of engine oils. The High Temperature/High Shear Test (HTHS) measures a lubricantís viscosity under severe operating conditions. The NOACK Volatility Test measures the evaporation loss of oils in high temperature service. Pour Point indicates the lowest temperature at which a fluid will flow. Total Base Number (TBN) is the measurement of a lubricantís reserve alkalinity for combating acids. The Cold Cranking Simulator Test (CCS) measures a lubricantís viscosity at low temperatures and high shear rates. The Four-Ball Wear Test measures a lubricantís wear protection properties. The impressive test results show AMSOIL Synthetic 10W-30 Motor Oil outperformed the competitors in each test.


Thin-Film Oxygen Uptake (motor oil test - ASTM D-4742):
The Thin-Film Oxygen Uptake Test evaluates the oxidation stability of lubricating oils. A mixture of the test oil and chemistries found in gasoline engine operation (oxidized/nitrated fuel, soluble metals and distilled water) are placed in a test vessel, which is pressurized with oxygen and placed in a heated bath. Anti-oxidant breakdown is evident when the oxygen pressure in the vessel rapidly decreases. At this point, the induction time (break point) of the oil is recorded. As shown in the graph, AMSOIL Synthetic 10W-30 Motor Oil had the highest induction time of all the tested oils. In fact, it didnít reach its break point in over 500 minutes of testing.

The superior oxidation stability of AMSOIL Synthetic 10W-30 Motor Oil allows it to effectively resist the formation of engine deposits and sludge, keeping engines running clean and efficient and extending oil life. It also resists thickening, maintaining its superior wear protection and lubricating properties and maximizing fuel efficiency.


High Temperature/High Shear (motor oil test - ASTM D-4683):
The High Temperature/High Shear Test measures a lubricantís viscosity under severe high temperature and shear conditions that resemble highly-loaded journal bearings in fired internal combustion engines. In order to prevent bearing wear, it is important for a lubricant to maintain its protective viscosity under severe operating conditions. The minimum High Temperature/High Shear viscosity for a 30 weight oil is 2.9 cP. As shown in the graph, AMSOIL Synthetic 10W-30 Motor Oil surpasses this minimum standard and displayed the highest High Temperature/High Shear viscosity in the group.

The superior viscosity retention of AMSOIL Synthetic 10W-30 Motor Oil in the face of severe temperature and shear conditions allows it to provide continuous, unsurpassed protection for engine bearings, extending equipment life and preventing wear.


NOACK Volatility (motor oil test - ASTM D-5800):
The NOACK Volatility Test determines the evaporation loss of lubricants in high temperature service.The more motor oils vaporize, the thicker and heavier they become, contributing to poor circulation, reduced fuel economy and increased oil consumption, wear and emissions. A maximum of 15 percent evaporation loss is allowable to meet API SL and ILSAC GF-3 specifications. As shown in the graph, AMSOIL Synthetic 10W-30 Motor Oil outperformed its nearest competitor by over 30 percent.

The extremely low volatility of AMSOIL Synthetic 10W-30 Motor Oil allows it to maintain its superior protective and performance qualities throughout extended drain intervals, even when faced with severe operating temperatures. In addition, oil consumption and emissions are minimized and fuel efficiency is maximized.


Pour Point (motor oil test - ASTM D-97):
The Pour Point Test determines the lowest temperature at which a lubricant will flow when cooled under prescribed conditions. The lower a lubricantís pour point, the better protection it provides in low temperature service. As shown in the graph, AMSOIL Synthetic 10W-30 Motor Oil has the lowest pour point of the tested oils.

The low pour point of AMSOIL Synthetic 10W-30 Motor Oil allows it to maintain its fluidity in extremely low temperatures, reducing drag on moving vehicle parts, providing critical engine components with quick, essential lubrication and easing startup in cold temperatures. Wear is greatly reduced and equipment life is extended.


Total Base Number (motor oil test - ASTM D-2896):
Total Base Number (TBN) is the measurement of a lubricantís reserve alkalinity, which aids in the control of acids formed during the combustion process. The higher a motor oilís TBN, the more effective it is in suspending wear-causing contaminants and reducing the corrosive effects of acids over an extended period of time. As shown in the graph, AMSOIL Synthetic 10W-30 Motor Oil has the highest TBN of the tested oils.

The high TBN of AMSOIL Synthetic 10W-30 Motor Oil allows it to effectively combat wear-causing contaminants and acids, providing superior protection and performance over extended drain intervals.


Cold Crank Simulator (motor oil test - ASTM D-5293):
The Cold Crank Simulator Test determines the apparent viscosity of lubricants at low temperatures and high shear rates. Viscosity of lubricants under these conditions is directly related to engine cranking and startability. The lower a lubricantís cold crank viscosity, the easier an engine will turn over in cold temperatures. 10W motor oils are tested at -25°C and must have a viscosity below 7000 cP to pass. As shown in the graph, AMSOIL Synthetic 10W-30 Motor Oil is well below the maximum requirement, while many of the competing oils barely pass.

The low cold crank viscosity of AMSOIL Synthetic 10W-30 Motor Oil reduces drag on moving engine parts and allows engines to achieve critical cranking speed in extremely frigid temperatures. Engines turn over quickly and dependably in the coldest winter temperatures.


Four Ball Wear (motor oil test - ASTM D-4172):
The Four Ball Wear Test determines the wear protection properties of a lubricant. Three metal balls are clamped together and covered with the test lubricant, while a rotating fourth ball is pressed against them in sliding contact. This contact typically produces a wear scar, which is measured and recorded. The smaller the average wear scar, the better the wear protection provided by the lubricant. As shown in the graph, AMSOIL Synthetic 10W-30 Motor Oil produced the smallest wear scar of the tested lubricants.

AMSOIL Synthetic 10W-30 Motor Oil provides unsurpassed protection against engine wear. Equipment life is extended, and repairs, downtime and expenses are reduced.


AMSOIL INC. has been the leader in synthetic motor oil formulation since its introduction of the worldís first API rated synthetic motor oil in 1972. By specializing exclusively in synthetic lubricant technology, AMSOIL is able to optimize the most advanced chemistries available. The ďGenuine Synthetic PAO FormulatedĒ designation displayed on AMSOIL packaging indicates that the oils are formulated with Polyalphaolefin (PAO) synthetic base stocks. This chemistry is the industryís premier base stock technology. Unlike conventional mineral-based chemistries, AMSOIL PAO base stocks contain fully saturated, hydrogenated molecules and are free of wax and other impurities. Combined with an exact balance of premium additives, it delivers superior hot and cold temperature performance, resists oxidation and acid formation and provides long-term wear protection. AMSOIL ďGenuine Synthetic PAO FormulatedĒ oils have shattered the parameters of the most rigorous industry motor oil tests and set the standard for all other motor oils.


Thinking all motor oil is the same? Think again!

AMSOIL is the undisputed leader in synthetics.............

Since 1972, AMSOIL Synthetics have proven to be the BEST. AMSOIL also engineers and manufactures Ea Oil Filters with Nanofiber Technology which have a 25,000 mile/1-year service life as well as specialized filtration systems for commercial and fleet applications in cars and light, medium and heavy trucks which can filter particles down to less than one micron (a standard full flow oil filter can only filter to 20-25 microns, and at a reduced efficiency) making oil changes virtually unnecessary and virtually eliminating engine wear. These filters have been proven by millions of miles of over-the road trucks, construction equipment and fleet service.

AMSOIL saves you time and money.
The only 25,000 mile/one- year and 35,000/one- year motor oil in the world.
Exceeds the most stringent performance specifications of all major U.S. and foreign automotive and truck manufacturers.
Provides up to two-times the wear protection of other motor oils.
Increases the life of your vehicle.
Improves performance, fuel economy and efficiency.
Diesel oil and filtration products designed to deliver 1,000,000 miles for over-the-road trucks before engine overhaul.
Used by many national racing teams, fleets, police departments, construction firms and trucking companies.

AMSOIL Synthetic Lubricants and Filtration products dramatically improve your vehicles performance, fuel economy and extend engine life. Independently Tested and Proven Best Synthetic Motor Oil. AMSOIL the Smart Synthetics!