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 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.

FIG. 1 Schematic of Engine Fuel System

5.2 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 D4485). This test method is also 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.

1.1 This test method covers and is commonly referred to as the Sequence VG test,2 and it has been 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 SL 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 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

Additional Measurements

13.7

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

16

Keywords

17

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