by Robert Sanborn on Thu, Jun 21, 2007, who was a member of the STLE Society of Tribologists and Lubrication Engineers for 15 years.
What are they?
Antiwear/Extreme Pressure Agents: These agents bond to metal surfaces to create a strong lubricant film between moving metal parts. This film can withstand extreme heat and mechanical pressure to keep metal parts separated, protecting them from scoring and seizing.
So Are Additives that Reduce Extreme Pressure Really Necessary?
According to the American Petroleum Institute (API) or the major oil companies spokesman, which is published in their Motor Oil Guide, they claim the following: “Extreme pressure conditions can develop between heavily loaded parts from lack of lubrication, inadequate clearance, extreme heat, and sometimes as a result of using the wrong type or grade of lubricant for the operating conditions of the engine. In modern engines the valve train with its cams, valve lifters, push rods, valve stem tips, and parts of the rocker arms operate under extreme pressure because they carry heavy loads on very small contact areas. Unit loading, which may be as high as 200,000 pounds per square inch, is many times greater than the loads on the connecting rod bearings or on the piston pins.” Because of higher unit loading, higher engine speeds, and the smaller size of certain parts, modern engines have many components that operate under boundary or extreme pressure conditions much of the time”.
Do Motor Oils Contain Extreme Pressure Additives?
Research has shown that NO motor oils contain extreme pressure additives presently. This includes major motor oil company’s petroleum and synthetic products as well as specialty synthetic motor oil producers such as Amsoil® , Redline®, and Royal Purple®.
If you find an oil you think contains extreme pressure agents let us know, we will be happy to look into it and test for its ability to handle extreme pressure using a similar method in the official ASTM test.
Which oil additives contain extreme pressure agents? How well do they work?
|**Name of Product**||**Load Wear Index**||**Seizure-Weld Load**|
|Protecta Engine Treatment®||187.7||No Seizure|
|Motorkote™||158.07||(seized) 620 Kilograms|
|Prolong®||152.8||(seized) 800 Kilograms|
|Energy Release®||111.7||(seized) 620 Kilograms|
|Slick 50®||37.04||(seized) 250 Kilograms|
|Duralube®||32.73||(seized) 200 Kilograms|
|Mobil 1® Tri-Synthetic motor oil||28.96||(seized) 200 Kilograms|
|Lucas® oil stabilizer||21.42||(seized) 126 Kilograms|
What does all this mean?
Load-wear Index: (or the load-carrying property of a lubricating fluid)– an index of the ability of a lubricant to minimize wear at applied loads. Under the conditions of this test, specific loading in kilogram having intervals of approximately 0.1 logarithmic units, are applied to the three stationary balls for ten runs prior to welding. Corrected load, kgf = LDh/X Where L = applied load multipled by the lever arm ratio. Dh = Hertz scar diameter, mm and X = average scar diameter. This equation reflects the ability of a lubricant both to carry a high load without welding and to allow only realtively small wear scars at loads below the weld point. In other words the higher the wear index the more pressure the lubricant can withstand before the metal bearings weld together. It should be noted that Protecta Engine Treatment® never reached seizure because the load required to cause seizure was above and beyond the machine’s highest parameters. It literally beat the machine.
Weld point: under the conditions of this test, the lowest applied load in kilograms at which the rotating ball welds to the three stationary balls, indicating the extreme-pressure level of the lubricating fluid has been exceeded. The only additive that did not reach a weld point in this test was Protecta Engine Treatment®.
All products, except Motorkote™, were tested without dilution at 100% concentration by Petro-Lubricant Test Labs, Inc. in New Jersey. Motorkote™ values were taken from their website thus we are unable to vouch for accuracy. It should be noted that we make no claims of any products tested except to provide the values through conducting the American Society of Testing Materials standardized test D-2783 as performed by the independent laboratory.
For the official ASTM certified test visit ASTM-D-2783