Synthetic Motor Oil Comparison

The Four Ball Wear Test evaluates the wear protection that an engine oil provides. Although not widely used as an engine oil test, the Four-Ball Wear Test provides a means of comparing relative wear-protection properties of lubricating oils.

The Four Ball Wear Test puts one rotating ½-inch diameter steel ball against three fixed ½-inch diameter steel balls, which are covered with the test lubricant, under specific conditions of pressure, temperature, revolutions per minute and duration. (To better differentiate between lubricants, the severity of this test was increased with higher rpm and temperature). Wear scars are then measured and averaged; the size of the scar determines the amount of wear protection the lubricant provides.

The smaller the wear scar, the better the protection.

• Extends engine life
• Major repairs are often reduced
• Reduced downtime and maintenance expenses

Total Base Number (TBN) is the measure of a lubricant’s reserve alkalinity, which aids in the control of acids formed during the combustion process. Most passenger car motor oils offer only 7 TBN and are formulated with detergents that quickly lose TBN value. With TBN loss, oils lose their ability to neutralize acids, prevent high-temperature deposits and inhibit rust. TBN can also be used as a measure of lubricant degradation in service; TBN loss is a primary reason oils require changing.

Motor oils that have a high TBN and demonstrate good TBN retention are known to effectively reduce the corrosive effects of acids over an extended period.

• Suspends wear-causing contaminants
• Longer oil life, reducing oil changes and saving time and money

The Cold Cranking Simulator Test determines the apparent viscosity of lubricants at low temperatures and at high shear rates. Viscosity of lubricants under these conditions is directly related to low-temperature engine cranking. The test results are used to assign SAE “W” grades. The test was performed at -22ºF (-30ºC). Results are reported in centipoise (cP). To meet the API SN and ILSAC GF-5 motor oil specifications, a motor oil’s cold crank viscosity must not exceed 6,600 cP.

The lower a lubricant’s cold crank viscosity, the easier an engine will turn over in cold temperatures. (Oils that thicken too much in cold temperatures won’t allow engines to turn fast enough to start.)

• Reduces drag on moving engine parts
• Allows engines to achieve critical cranking speed in frigid temperatures
• Engines turn over quickly and dependably in the coldest winter temperatures
• Oil flows quickly to engine parts for critical start-up protection
• Wear is greatly reduced
• Reduces strain on battery

Motor oils can form deposits when exposed to increased heat, reducing efficiency and contributing to poor overall performance. Given the number of vehicles now equipped with direct fuel injection, turbochargers and other performance-enhancing technologies that increase heat, deposit control has taken on increased importance. To meet the API SN Resource Conserving and ILSAC GF-5 motor oil specifications, a 5w30 motor oil must limit total deposit formation to 30 mg or less.

According to the ASTM, the TEOST test method “is designed to predict the high-temperature deposit forming tendencies of an engine oil. This test method can be used to screen oil samples or as a quality assurance tool.”

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. The NOACK provides a basis for estimating the approximate useful life of a lubricant.

In the NOACK, a test specimen of oil is heated to 482°F and held at that temperature for one hour. After an hour, the remaining oil volume is weighed and compared to the original weight, with the difference reported as the percentage of weight lost. The NOACK Volatility Test was developed in Germany and has long been a specification test for European motor oils. Volatility testing became a requirement for North American motor oils in 1992, with the introduction of API SH/ILSAC GF-1 oils. Volatility standards were tightened with the 1996 introduction of API SJ/ILSAC GF-2 oils, which required a weight loss limit of 22%. Results must be limited to 15% or less to meet the current API SM/ILSAC GF-4 specifications.

According to the ASTM, “Evaporation may contribute to oil consumption in an engine and can lead to a change in the properties of an oil.” As with the TEOST test, low values in the NOACK Volatility Test are of particular benefit in modern, hot-running engines. Lubricants with low NOACK scores are preferred; the lower the number, the better the resistance to vaporization. Low NOACK scores indicates an oil that will keep their original protective and performance qualities longer.

• Better oil circulation
• Maximum fuel efficiency
• Reduced oil consumption
• Less deposit formation
• Stable viscosity for low and high temperature wear protection
• Fewer emissions
• Longer oil life, reducing oil changes and saving time and money

The value comparison chart below shows how much money a motorist would spend on each of the oils tested and the number of oil changes required.

The above tests prove AMSOIL’s ability to safely extend oil drain intervals, but the value comparison chart below illustrates what an impact AMSOIL will have on your time and wallet. AMSOIL saves drivers both time and money!