ASTM D5966-22 - 1.4.2022
 
Significance and Use

5.1?This test method is used to determine the ability of an engine crankcase oil to control wear that can develop in the field under low to moderate engine speeds and heavy engine torques. Side-by-side comparisons of two or more oils in delivery van fleets were used to demonstrate the field performance of various oils. The specific operating conditions of this test method were developed to provide correlation with the field performance of these oils.

5.2?This test method, along with other test methods, defines the minimum performance level of the Category API CG-4 for heavy duty diesel engine lubricants. Passing limits for this category are included in Specification D4485.

5.3?The design of the engine used in this test method is not representative of all modern diesel engines. Consider this factor, along with the specific operating conditions used to accelerate wear, when extrapolating test results.

 
1. Scope

1.1?This engine lubricant test method is commonly referred to as the Roller Follower Wear Test. Its primary result, roller follower shaft wear in the hydraulic valve lifter assembly, has been correlated with vehicles used in stop-and-go delivery service prior to 1993. It is one of the test methods required to evaluate lubricants intended to satisfy the API CG-4 performance category. This test has also been referred to as the 6.2 L Test.

1.2?The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.2.1?ExceptionsWhere there is no direct SI equivalent, such as pipe fittings, thermocouple diameters, and NPT screw threads. Also, roller follower wear is measured in mils.

1.3?This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.4?Table of Contents:

?

Section

Scope

1

Referenced Documents

2

Terminology

3

Summary of Test Method

4

Significance and Use

5

Reagents

7

Guidelines on Substitution

7.1

Apparatus

6

Preparation of Apparatus

8

New Engine Preparation

8.1

Installation of Auxiliary Systems and
Miscellaneous Components

8.2

Test Procedure

9

Description of Test Segments and Organization
of Test Procedure Sections

9.1

Engine Parts Replacement

9.2

Engine Starting Procedure

9.3

Normal Engine Shutdown Procedure

9.4

Emergency Shutdown Procedure

9.5

Unscheduled Shutdown and Downtime

9.6

New Engine Break-In

9.7

Pretest Procedure

9.8

Fifty-Hour Steady State Test

9.9

Periodic Measurements

9.10

Oil Sampling and Oil Addition Procedures

9.11

End of Test (EOT) Procedure

9.12

Calculation and Interpretation of Test Results

10

Environment of Parts Measurement Area

10.1

Roller Follower Shaft Wear Measurements

10.2

Oil Analysis

10.3

Assessment of Test Validity

10.4

Final Test Report

11

Reporting Calibration Test Results

11.1

Report Forms

11.2

Interim Non-Valid Calibration Test Summary

11.3

Severity Adjustments

11.4

Precision and Bias

12

Precision

12.1

Precision Estimate

12.2

Bias

12.3

Keywords

13

ANNEXES

Guidelines for Test Part Substitution or Modification

Annex A1

Guidelines for Units and Specification Formats

Annex A2

Detailed Specifications of Apparatus

Annex A3

Calibration

Annex A4

Final Report Forms

Annex A5

Illustrations

Annex A6

Kinematic Viscosity at 100?C Procedure for the
Roller Follower Wear Test

Annex A7

Enhanced Thermal Gravimetric Analysis (TGA)
Procedure for Soot Measurement

Annex A8

Sources of Materials and Information

Annex A9

APPENDIXES

PC-9 Reference Diesel Fuel Properties

Appendix X1

Diagnostic Data Review

Appendix X2

1.5?This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

 
2. Referenced Documents

D524-15(2025)e1

Standard Test Method for Ramsbottom Carbon Residue of Petroleum Products (Includes all amendments and changes 8/11/2025).

D287-22

Standard Test Method for API Gravity of Crude Petroleum and Petroleum Products (Hydrometer/Method)

D97-17b(2022)

Standard Test Method for Pour Point of Petroleum Products (Includes all amendments and changes 11/29/2022).

D93-26

Standard Test Methods for Flash Point by Pensky-Martens Closed Cup Tester

D130-26

Standard Test Method for Corrosiveness to Copper from Petroleum Products by Copper Strip Test

D235-22

Standard Specification for Mineral Spirits (Petroleum Spirits) (Hydrocarbon Dry Cleaning Solvent)

D613-25a

Standard Test Method for Cetane Number of Diesel Fuel Oil (Includes all amendments and changes 11/6/2025).

D86-23ae2

Standard Test Method for Distillation of Petroleum Products and Liquid Fuels at Atmospheric Pressure (Includes all amendments and changes 11/4/2024).

D445-24

Standard Test Method for Kinematic Viscosity of Transparent and Opaque Liquids (and Calculation of Dynamic Viscosity)

D446-24

Standard Specifications and Operating Instructions for Glass Capillary Kinematic Viscometers

D482-25

Standard Test Method for Ash from Petroleum Products

D7422-25

Standard Test Method for Evaluation of Diesel Engine Oils in T-12 Exhaust Gas Recirculation Diesel Engine

E29-22

Standard Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications

MC96.1

Temperature Measurement Thermocouples

D5185-26

Standard Test Method for Multielement Determination of Used and Unused Lubricating Oils and Base Oils by Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES)

D4737-21

Standard Test Method for Calculated Cetane Index by Four Variable Equation

D976-21e1

Standard Test Method for Calculated Cetane Index of Distillate Fuels (Includes all amendments and changes 2/23/2023).

D1319-25

Standard Test Method for Hydrocarbon Types in Liquid Petroleum Products by Fluorescent Indicator Adsorption

D2274-14(2019)

Standard Test Method for Oxidation Stability of Distillate Fuel Oil (Accelerated Method)

D2500-23

Standard Test Method for Cloud Point of Petroleum Products and Liquid Fuels

D2622-26

Standard Test Method for Sulfur in Petroleum Products by Wavelength Dispersive X-ray Fluorescence Spectrometry

D2709-22

Standard Test Method for Water and Sediment in Middle Distillate Fuels by Centrifuge

D4052-22

Standard Test Method for Density, Relative Density, and API Gravity of Liquids by Digital Density Meter

D4175-24e1

Standard Terminology Relating to Petroleum Products, Liquid Fuels, and Lubricants (Includes all amendments and changes 11/19/2024).

D664-24

Standard Test Method for Acid Number of Petroleum Products by Potentiometric Titration

D4485-24

Standard Specification for Performance of Active API Service Category Engine Oils