ASTM D6681-05 - 1.11.2005
 
Significance and Use

This is an accelerated engine oil test, performed in a standardized, calibrated, stationary single-cylinder diesel engine that gives a measure of (1) piston and ring groove deposit forming tendency, (2) piston, ring and liner scuffing and (3) oil consumption. The test is used in the establishment of diesel engine oil specification requirements as cited in Specification D 4485 for appropriate API Performance Category C oils (API 1509). The test method can also be used in diesel engine oil development.

 
1. Scope

1.1 This test method is required to evaluate the performance of engine oils intended to satisfy certain American Petroleum Institute (API) C service categories (included in Specification D 4485). It is performed in a laboratory using a standardized high-speed, single-cylinder diesel engine. Piston and ring groove deposit-forming tendency and oil consumption is measured. The piston, the rings, and the liner are also examined for distress and the rings for mobility.

1.2 All measurements made in accordance with this standard shall use the SI system of units.

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. Being an engine test method, this standard does have definite hazards that require safe practices (see on Safety).

 
2. Referenced Documents

D97-17b(2022)

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

D130-26

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

D86-23ae2

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

D93-26

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

D235-22

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

D445-26

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

D482-25

Standard Test Method for Ash from Petroleum Products

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)

D5862-09

Standard Test Method for Evaluation of Engine Oils in Two-Stroke Cycle Turbo-Supercharged 6V92TA Diesel Engine (Withdrawn 2009)

D6202-02

Standard Test Method for Automotive Engine Oils on the Fuel Economy of Passenger Cars and Light-Duty Trucks in the Sequence VIA Spark Ignition Engine (Withdrawn 2009)

D6593-18e1

Standard Test Method for Evaluation of Automotive Engine Oils for Inhibition of Deposit Formation in a Spark-Ignition Internal Combustion Engine Fueled with Gasoline and Operated Under Low-Temperature, Light-Duty Conditions (Includes all amendments and changes 6/22/2022).

D7422-25

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

API 1509

ASTM Deposit Rating Manual 20

(formerly CRC Manual 20) For Stock #TMCMNL20, visit the ASTM website, www.astm.org, or contact ASTM International Customer Service at service@astm.org.

E29-22

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

G40-25a

Standard Terminology Relating to Wear and Erosion (Includes all amendments and changes 12/8/2025).

D664-24

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

D4739-26

Standard Test Method for Base Number Determination by Potentiometric Hydrochloric Acid Titration

D3524-14(2020)

Standard Test Method for Diesel Fuel Diluent in Used Diesel Engine Oils by Gas Chromatography

D4175-24e2

Standard Terminology Relating to Petroleum Products, Liquid Fuels, and Lubricants (Includes all amendments and changes 6/9/2026).

D4052-22

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

D4485-24

Standard Specification for Performance of Active API Service Category Engine Oils

D3227-24

Standard Test Method for (Thiol Mercaptan) Sulfur in Gasoline, Kerosine, Aviation Turbine, and Distillate Fuels (Potentiometric Method)

D2274-14(2019)

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

D2425-23

Standard Test Method for Hydrocarbon Types in Middle Distillates by Mass Spectrometry

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

D524-15(2025)e1

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

D613-26

Standard Test Method for Cetane Number of Diesel Fuel Oil

D1319-26

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