The True Measure of Lubricant Quality

Measures That Matter

The American Society for Testing and Materials recognized the need for uniform procedures that can be duplicated and verified by laboratories in any location. The goal of establishing standards is so important that the official publication of ASTM International is called Standardization News.

Founded in 1898 and completely voluntary, ASTM is now one of the largest non-profit standards development systems in the world. The organization currently has 134 committees that write standardized test methods for materials, products, systems and services. More than 8500 ASTM specifications have been established for products as diverse as metal, paints, plastics, textiles, energy, consumer products, medical services and instruments and even the environment.

Developing standard measurement methods is part of the task of ASTM. Equally important is determining what measures are important, tests that actually correspond to what the function of motor oil is intended to fulfill. What follows here are some tests commonly used to evaluate motor oil performance.

ASTM D-445 Kinematic Viscosity

The proper operation of equipment depends on the proper kinematic viscosity of the oil at operating temperatures. Kinematic viscosity is a measure of a liquid's flow under the influence of gravity. Some companies formulate their lubes to tighter specs than others. One recent study revealed that one in five off-the-shelf motor oils tested were outside the acceptable performance range for their stated viscosities.

ASTM D-2270 Viscosity Index

This test indicates how much a lube's viscosity will change according to changes in temperature from 40 degrees C and 100 degrees C. The higher the viscosity index the better for motor oils that must perform in locations with temperature variations.

ASTM D-5293 Cold Crank Simulator Apparent Viscosity

Cold crank viscosity affects the startability of engines in cold temperatures. Low cold cranking viscosities make for easier cold cranking and more dependable cold temperature starting, and less drain on batteries.

ASTM D-3829 Borderline Pumping Temperature

This test is used to predict the lowest temperature at which a motor oil can be continuously and adequately supplied to an engine¹s components. As the name suggests, the lower the temperature, the better the oil circulates in cold weather. Synthetic oils are famed for the extreme low temperature protection.

ASTM D-97 Pour Point

This test identifies the lowest temperature at which oil flows.

ASTM D-92 Flash Point and Fire Point

Flash point indicates the temperature at which a specimen vapors will ignite.
Flash point assesses the overall hazard of a material and is used in shipping and safety regulations to define "flammable" and "combustible" materials. Fire point measures the temperature at which a specimen will remain burning for five seconds. Synthetic lubricants with high flash and fire points are safer to use and transport than petroleum lubes with lower ones. High flash point is indicative of a greater high temperature operating range and better quality base stock.

ASTM D-4683 High Temp, High Shear Viscosity

This test is representative of the conditions encountered in the bearings of automotive engines in severe service. Lubricants with high scores, such as premium synthetics, maintain their viscosity in high temperatures after exposure to high shear. This means that they continue to protect bearings even after exposure to severe service conditions.

ASTM D-892 Foaming Tendency

This test is important because of the turbulent environment in which motor oils are required to perform. Foaming can lead to inadequate lubrication, cavitation and mechanical failure.

ASTM D-4172B Four Ball Wear Test

The Four Ball Wear Test determines the relative wear prevention properties of lubricants in sliding contact. The test involves three fixed balls in a bath of lubricant with a fourth ball in rolling contact under pressure at a specific level of severity. Wear protection is gauged by measuring the wear scar that develops. A smaller wear scar means better protection in typical engine operations.

ASTM D-5800 Noack Volatility

Oil volatility is the measure of how susceptible oil is to boil-off under high heat conditions. Petroleum oils experience significant boil-off during high temperature engine operation and subsequently higher oil consumption. Evaporation loss contributes to damaging deposits, sticky piston rings and oil blow-by, resulting in a drag on performance and reduced engine life. Synthetic oils are far more impervious to this kind of degradation. The lower volatility of synthetics is another reason they are also better for the environment than conventional products.

SAE J1321 Joint TMC/SAE Fuel Consumption Test Procedure - Type II

The Society of Automotive Engineers has devised a test to measure fuel consumption and fuel economy. In a demonstration involving over-the-road trucks an improvement of 8.2% was achieved by switching from conventional lubes to synthetic lubricants (in this case AMSOIL products) in the drivetrain and engine.

Here's an interesting, undisputed fact. By every one of these measures premium synthetic motor oils are superior to conventional petroleum motor oils. This truth is never even questioned by industry professionals.

So why, one might ask, isn't everyone using synthetic motor oils and lubes? Here's one possible reason. To divert attention away from the performance measures above the major oil companies focus on one other measure: price.

Additional Info via the Links Below:

page 1 : Introduction
page 2 : Oil Measures
page 3 : The Role of Motor Oil
page 4 : Synthetic Vs. Conventional Petroleum
page 5 - current : Measures That Matter
page 6 : Price