What is the Four Ball Wear Test?

AMSOIL Series 2000 Synthetic 20W-50 Racing Oil (TRO) displays on its label a chart showing the performance of various motor oils on the Four Ball Wear Test, ASTM D-4172. Just what is the test and what do the results tell motorists? The Action News talked to Director of Lubricants Technology H. Lefty Ward to find out.

What is the Four Ball Wear Test? How good a predictor of engine wear is it?

The Four Ball Wear Test puts one rotating ball against three fixed balls under specific conditions of pressure, temperature, revolutions per minute and duration. The test may be used to evaluate the friction- and wear-control ability of liquid lubricants or greases in sliding contact. The Four Ball Wear Test is a good laboratory tool for developing oils with good engine wear control.

The results appearing on the TRO label were from testing done by an independent lab. Did the lab favor AMSOIL because AMSOIL paid for the tests?

AMSOIL sent its samples to a very well-known independent testing facility. That facility would not jeopardize its reputation by misrepresenting test results.

We ran literally thousands of tests in our own lab before we sent the product for testing. The independent lab’s results correlate very well with our own.

Why did AMSOIL choose to test TRO at 60 kg of force, 1500 C, 1800 rpms and 60 minutes duration? Do those parameters correspond to actually engine conditions?

The standard conditions under which the ASTM D-4172 test is run are 40 kg force; 75° C or 150° C; 600 rpm, 1200 rpm or 1800 rpm; and 60 minutes. AMSOIL tested at more severe parameters to really determine the quality of the anti-wear film. By increasing the load, we put much more stress on the oil film. The extra load works to squeeze the oil from between the contacting surfaces. Once the oil is squeezed from between the surfaces, wear results.

Under the increased pressure of the parameters, we chose for the test, TRO maintained excellent film integrity, as evidenced by a small wear scar. Other oils sustained interruptions of film integrity, as evidenced by large wear scars.

Is subjecting a sample of used oil to Four Ball Wear testing a valid procedure?

Absolutely not. Too many variables remain uncontrolled to give meaningful results. For example, was the used oil contaminated with fuel? With glycol? What kind of fuel was used in the engine? Oxygenated fuels affect oils differently than non-oxygenated fuels do.

The Four Ball Wear Test is meant to be run on new (unused) samples. In fact, all ASTM test procedures are designed to be used on unused samples.

If people want to know about the integrity of their engines and engine oils, they should have regular used oil analysis performed and assess the wear metals findings over the course of many samplings.

Similarly, one oil cannot be compared to another unless both oils are tested in controlled settings and used oil analysis trendlines are followed, as AMSOIL has done in its commercial demonstrations.

How does TRO perform in the field?

Racers across the country have been using it and they are extremely pleased with the results. As you know, engine builders have been dyno-testing the oil and are excited about the results: TRO gives more horse-power and more torque than other oils do. More horsepower and torque wins races. But nobody’s going to throw an engine away to excessive wear, no matter how much more speed they get. So clearly, they are happy with the overall performance of the oil, including wear performance.

*All trademarked names and images are the property of their respective owners and may be registered marks in some countries. No affiliation or endorsement claim, express or implied, is made by their use. All products advertised here are developed by AMSOIL for the use in the application shown.

Reproduced With The Permission Of AMSOIL INC. All Rights Reserved.

SLS Note: While the TRO Series 2000 Racing Oil is no longer in production, it has been replaced by an even better expanded line of Dominator Racing Lubricants.

If you would like to know just how well your oil is holding up, AMSOIL has oil analysis kits available. While doing your oil change you use the sample bottle to catch several ounces of the drain oil as it comes out of the pan. Complete the needed information on the included paperwork and send the sample off to the lab. AMSOIL uses Oil Analyzers Inc., a division of Polaris Labs which is one of the leaders in oil analysis in the country. Will try and post a sample report in the near future. Look for it in the Miscellaneous Information section of the site.

For more information on any AMSOIL Product contact SLS Associates. We’ll give you the information, you make the decisions.

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