Heard of the Timken Extreme Pressure Bearing Oil test? I just learned it's useless in car engine oil tests, and was designed for gear lube and grease

on http://forums.tdiclub.com/showthread.php?t=147342

they have written
The problem with this 'test' is that it's not designed for engine oil, engine oil in general doesn't use EP additives because engines don't need them. Both Schaeffer and Royal Purple reps crank on the machine until the metal is digging away and smoking. Impressive demonstration for a farm show, but useless for demonstrating real oil performance. If you ever come up on this test by an oil or additive vendor, bring out a little bottle of Head and Shoulders shampoo (smells better) or bleach or phosphoric acid (or some Coke). These will beat any oil on the market in this 'test'...

[For more info on the use of the Timken EP test, reference this article from Machinery Lubrication magazine, written by Mr. Ludwig, Chief Chemist/Tech Director of Schaeffer. From the article: "Any test results that are obtained by the use of this test method have been found not to correlate with results obtained during field service."] http://www.machinerylubrication.com/article_detail.asp?articleid=616 for the full write up, and links to the other tests

But here is the relavant part
Timken EP Test ASTM D2783

The Timken EP Test ASTM D2783 provides a rapid method for measuring the abrasion resistance and the load-carrying capabilities of industrial gear lubricants. The test method is widely used for specification purposes and to differentiate industrial gear lubricants that have low, medium and high levels of extreme pressure characteristics. Any test results that are obtained by the use of this test method have been found not to correlate with results obtained during field service.

During the test, one gallon of the industrial gear lubricant being tested is placed into the test mechanism’s reservoir. The tester is operated with a Timken tapered roller cup rotating against a stationary hardened steel block at a rotating speed of 405.88 ±2.54 ft/min., which is equivalent to a speed of 800 rpm. The industrial gear lubricant sample is brought to a test temperature of 100°F (38ºC), and applied to the test cup and block by gravity from the one-gallon reservoir and by a scavenging pump that returns the lubricant to the reservoir. Two determinations are made: the minimum load (score value) that will rupture the lubricant film between the rotating cup and the stationary block and cause abrasion; and the maximum load (OK load) at which the rotating cup will not rupture the lubricant film and cause abrasion between the rotating cup and the stationary block. Fixed weights acting through a 10-to-1 ratio lever arm are applied by an automatic loading device in order to force the block into contact with the rotating test cup. Each load is applied for 10 minutes. At the end of each 10-minute run, the stationary test block is examined for scoring. Scoring is indicated when the edges of the wear scar becomes uneven. The OK load is the last load before scoring has occurred.
Here are my videos of the Justice Brothers oil reps using that test to prove how awesome their oil additives are http://justacarguy.blogspot.com/2009/11/if-you-se-eit-you-can-believe-it-better.html

It is a really impressive test, and definitely shows how the metal to metal is going to happen with the competitions oil. Now, I'd never seen the test before, and hadn't heard of this (above) disclaimer on the relavancy of the test.

for a really well written look at the "Wonder Oils" and additives like Slick 50, read http://www.skepdic.com/slick50.html

The basic ingredient is the same in most of these additives: 50 weight engine oil with standard additives. The magic ingredient in Slick 50, Liquid Ring, Matrix, QM1 and T-Plus from K-Mart is Polytetrafluoroethylene. Don't try to pronounce it: call it PTFE. But don't call it Teflon, which is what it is, because that is a registered trademark. Dupont, who invented Teflon, claims that "Teflon is not useful as an ingredient in oil additives or oils used for internal combustion engines." But what do they know? They haven't seen the secret studies done by Petrolon (Slick 50).

PTFE is a solid which is added to engine oil and coats the moving parts of the engine.

In defense of Slick 50, tests done on a Chevy 6 cylinder engine by the University of Utah Engineering Experiment Station found that after treatment with the PTFE additive the test engine's friction was reduced by 13.1 percent, the output horsepower increased from 5.3 percent to 8.1 percent, and fuel economy improved as well. Unfortunately, the same tests concluded that "There was a pressure drop across the oil filter resulting from possible clogging of small passageways." Oil analysis showed that iron contamination doubled after the treatment, indicating that engine wear increased (Rau).

In 1997, three subsidiaries of Quaker State Corp. (the makers of Slick 50) settled Federal Trade Commission charges that ads for Quaker State's Slick 50 Engine Treatment were false and unsubstantiated.

In fact, the FTC said, "most automobile engines are adequately protected from wear at start-up when they use motor oil as recommended in the owner's manual. Moreover, it is uncommon for engines to experience premature failure caused by wear, whether they have been treated with Slick 50 or not." 

that is a very good point. Your engine is hardly at risk for bearing failure, or metal to metal wear. Why don't the car makers recommend oil additives? Or any of these super new ultra performing oil products? Well, it's worth thinking about

Timken had their own disclaimer on their website

http://www.timken.com/en-us/products/lubrication/Pages/faq.aspx

"Between 1935 and 1972, The Timken Company produced and sold a lubricant test machine that was used to determine the EP (extreme pressure) characteristics of grease and oil lubricants. It became an industry-standard test. A bearing race is mounted on a tapered arbor that is rotating at a high speed. A square, steel test block is then loaded against the rotating race, with the contact area flooded with the test lubricant. The load on the block is increased in increments until the oil film is broken and the spinning race produces a score mark on the test block. The load-value that produces the score is then called the Timken “O.K.” load rating.

It was generally assumed that the higher the O.K. value, the more load the lube could hold without the film strength being compromised. However, this is not necessarily the case, and the primary purpose of the test is to determine whether or not the lube has an EP additive. Values higher than 35 lbs. indicate the presence of an EP additive."