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

ASTM - ASTM International

ASTM D8256-25

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Year: 2025

Abstract: 5.1 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 VH test method was correlated with the previous VG test method, which 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. 5.2 This test method, along with other test methods are used to define an engine oils minimum performance level necessary to meet certification requirements for API Category Specifications as outlined in Specification D4485. This test method may also be incorporated in automobile manufacturers’ factory–fill specifications. 5.3 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.

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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

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contributor author	ASTM - ASTM International
date accessioned	2025-09-30T19:28:19Z
date available	2025-09-30T19:28:19Z
date copyright	2025
date issued	2025
identifier other	d8256-25.pdf
identifier uri	http://yse.yabesh.ir/std;jsery=autho/handle/yse/343753
description abstract	5.1 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 VH test method was correlated with the previous VG test method, which 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. 5.2 This test method, along with other test methods are used to define an engine oils minimum performance level necessary to meet certification requirements for API Category Specifications as outlined in Specification D4485. This test method may also be incorporated in automobile manufacturers’ factory–fill specifications. 5.3 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.
language	English
title	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	en
title	ASTM D8256-25	num
type	standard
status	Active
tree	ASTM - ASTM International:;2025
contenttype	fulltext
scope	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 Alternate Fuel Approval Requirements Annex A16 Surface Finish Analyzer Set Up and Holding Fixture Annex A17 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.
identifier DOI	10.1520/D8256-25