ASTM D8256-24A - Standard Test Method for Evaluation of Automotive Engine Oils for Inhibition of Deposit Formation in the Sequence VH Spark-Ignition Engine Fueled with Gasoline and Operated Under Low-Temperature, Light-Duty Conditions
Standard Test Method for Evaluation of Automotive Engine Oils for Inhibition of Deposit Formation in the Sequence VH Spark-Ignition Engine Fueled with Gasoline and Operated Under Low-Temperature, Light-Duty Conditions
| Standard number: | ASTM D8256-24A |
| Released: | 01.07.2024 |
| Status: | Active |
| Pages: | 91 |
| Section: | 05.05 |
| Keywords: | lubricating oils; Sequence VH; sludge and varnish; spark-ignition automotive engine; stop-and-go service; |
1.1 This test method is commonly referred to as the Sequence VH test, and it has been correlated with the Sequence VG test. The Sequence VG test was previously correlated with vehicles used in stop-and-go service prior to 1996, particularly with regard to sludge and varnish formation.3 It is one of the test methods required to evaluate oils intended to satisfy the API SN, SN Plus performance category.
1.2 The values stated in SI units are to be regarded as the standard. No other units of measurement are included in this standard.
1.2.1 Exception—Where there is no direct SI equivalent such as screw threads, national pipe threads/diameters, tubing size, or specified single source equipment.
1.3 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 VH 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 Torque | 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 (MAP) | 14.4 |
| Fuel Consumption Rate | 14.5 |
| Oil Consumption | 14.6 |
| Engine Parts Replacement | 14.7 |
| Quality Index | 14.8 |
| Final Test Report | 15 |
| Report Forms | 15.1 |
| Precision and Bias | 16 |
| Keywords | 17 |
| ANNEXES |
|
| ASTM TMC: Organization | Annex A1 |
| ASTM TMC: Calibration Procedures | Annex A2 |
| ASTM TMC: Maintenance Activities | Annex A3 |
| ASTM TMC: Related Information | Annex A4 |
| Safety Precautions | Annex A5 |
| Control and Data Acquisition Requirements | Annex A6 |
| Detailed Specifications and Photographs of Apparatus | Annex A7 |
| Test Engine Part Number, Classification, and Usage Guidelines | Annex A8 |
| External Oil Heat Exchanger Cleaning Technique | Annex A9 |
| Sequence VH Report Forms and Data Dictionary | Annex A10 |
| Dipstick Calibration | Annex A11 |
| Critical Part Supplier List | Annex A12 |
| Operational Data Log—Engine Oil | Annex A13 |
| Rating Worksheets | Annex A14 |
| Fuel Injector Flow Measurements | Annex A15 |
| APPENDIXES |
|
| Piston and Ring Measurements Record Forms | Appendix X1 |
| Sources of Materials and Information | Appendix X2 |
1.4 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. Specific hazard statements are given in 7.7, 7.7.1, 7.7.2, 7.7.3, 7.7.4, 7.7.5, A5.3.4, and A5.3.5.5.
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.