Significance and Use
This test method is used to evaluate an automotive engine oil's control of engine deposits under operating conditions deliberately selected to accelerate deposit formation. This test method was correlated with field service data, determined from side-by-side comparisons of two or more oils in police, taxi fleets, and delivery van services. The same field service oils were then used in developing the operating conditions of this test procedure.
This test method, along with other test methods, defines the minimum performance level of the API Category SL (detailed information about this category is included in Specification D 4485
The basic engine used in this test method is representative of many that are in modern automobiles. This factor, along with the accelerated operating conditions, should be considered when interpreting test results.
FIG. 1 Schematic of Engine Fuel System
Scope
1.1 This test method covers and is commonly referred to as the Sequence VG test, and it has been correlated with vehicles used in stop-and-go service prior to 1996, particularly with regard to sludge and varnish formation. It is one of the test methods required to evaluate oils intended to satisfy the API SL performance category.
1.2 The values stated in SI units are to be regarded as the standard. The values in parentheses are for information only.
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 and health practices and determine the applicability of regulatory limitations prior to use. Specific hazard statements are given in 7.7, 7.10.2.2, 8.3.4.2, 8.4.4.3, 9.2.6, 9.3.4.5, 12.1.1.7, 12.2.1.4, and Annex A1.
1.4 A Table of Contents follows:
| Section | ||
| Scope | 1 | |
| Referenced Documents | 2 | |
| Terminology | 3 | |
| Summary of Test Method | 4 | |
| Significance and Use | 5 | |
| Apparatus (General Description) | 6 | |
| Apparatus (The Test Engine) | 7 | |
| Sequence VG Test Engine | 7.1 | |
| Required New Engine Parts | 7.2 | |
| Reusable Engine Parts | 7.3 | |
| Specially Fabricated Engine Parts | 7.4 | |
| Special Engine Measurement and Assembly Equipment | 7.5 | |
| Miscellaneous Engine Components-Preparation | 7.6 | |
| Solvents and Cleaners Required | 7.7 | |
| Assembling the Test Engine-Preparations | 7.8 | |
| Assembling the Test Engine-Installations | 7.9 | |
| Engine Installation on the Test Stand | 7.10 | |
| Engine Fluids (Supply/Discharge Systems) | 8 | |
| Intake Air | 8.1 | |
| Fuel and Fuel System | 8.2 | |
| Engine Oil and Engine Oil System | 8.3 | |
| Coolants | 8.4 | |
| Measurement Instrumentation | 9 | |
| Temperatures | 9.1 | |
| Pressures | 9.2 | |
| Flow Rates | 9.3 | |
| Fuel Consumption | 9.4 | |
| Speed and Load | 9.5 | |
| Exhaust Gas | 9.6 | |
| Humidity | 9.7 | |
| Miscellaneous Laboratory Equipment | 10 | |
| Test Stand Calibration | 11 | |
| Test Procedure | 12 | |
| Pre-Test Procedure | 12.1 | |
| Engine Operating Procedure | 12.2 | |
| Periodic Measurements and Functions | 12.3 | |
| Special Maintenance Procedures | 12.4 | |
| Diagnostic Data Review | 12.5 | |
| End of Test Procedure | 12.6 | |
| Interpretation of Test Results | 13 | |
| Parts Rating Area-Environment | 13.1 | |
| Sludge Ratings | 13.2 | |
| Varnish Ratings | 13.3 | |
| Clogging | 13.4 | |
| Sticking | 13.5 | |
| Used Oil Analyses | 13.6 | |
| Assessment of Test Validity | 14 | |
| General | 14.1 | |
| Used Oil Analyses-Interpretation | 14.2 | |
| Blowby Flow Rate | 14.3 | |
| Manifold Absolute Pressure | 14.4 | |
| Fuel Consumption Rate | 14.5 | |
| Oil Consumption | 14.6 | |
| Engine Parts Replacement | 14.7 | |
| Quality Index and Deviation Percentage | 14.8 | |
| Final Test Report | 15 | |
| Report Forms | 15.1 | |
| Precision and Bias | 17 | |
| Keywords | 18 | |
| ANNEXES | ||
| Safety Hazards | Annex A1 | |
| Control and Data Acquisition Requirements | Annex A2 | |
| Detailed Specifications and Photographs of Apparatus | Annex A3 | |
| Special Service Tools for the Test Engine | Annex A4 | |
| Test Engine Part Number Listing | Annex A5 | |
| External Oil Heat Exchanger Cleaning Technique | Annex A6 | |
| Sequence VG Report Forms and Data Dictionary | Annex A7 | |
| Dipstick Calibration | Annex A8 | |
| Critical Part Supplier List | Annex A9 | |
| Operational Data Log-Engine Oil | Annex A10 | |
| Rating Worksheets | Annex A11 | |
| Fuel Injector Flow Measurements | Annex A12 | |
| APPENDIXES | ||
| Piston and Ring Measurements Record Forms | Appendix X1 | |
| Sources of Materials and Information | Appendix X2 | |
| Description of Scott Quarterly Gas Audit Service | Appendix X3 | |
