ASTM D976-06

Standard Test Method for Calculated Cetane Index of Distillate Fuels

SIGNIFICANCE AND USE
The Calculated Cetane Index is one tool available for estimating ASTM cetane number where a test engine is not available for determining this property. It may be employed for approximating cetane number where the quantity of sample is too small for an engine rating. In cases where the cetane number of a fuel has been initially established, the index is useful as a cetane number check on subsequent samples of that fuel, provided its source and mode of manufacture remain unchanged.
Test Method D 4737 may also be used to approximate the ASTM cetane number of diesel fuels.
3.2.1 Procedure A of Test Method D 4737 was developed as a result of a larger degree of offset between Test Method D 976 Cetane Index and the results of Test Method D 613 over the entire range of the correlation. Generally, it has been found that use of Test Method D 4737 results in less offset than use of Test Method D 976, but there can be specific cases where this is not true.
3.2.2 Procedure A of Test Method D 4737 is recommended to estimate the cetane number of diesel fuels with sulfur contents above 500 ppm or No. 1–D diesel fuels.
3.2.3 Procedure B of Test Method D 4737 is recommended to estimate the cetane number of No. 2–D diesel fuels with sulfur contents at or below 500 ppm.
Calculated Cetane Index, as described in Test Method D 976–80, is recognized by the United States EPA as an alternative method to meet the U.S. Federal Diesel aromatics limit for diesel fuels containing less than 500 ppm sulfur. The equation for Calculated Cetane Index in Test Method D 976–80 and in this version (D 976–06) of the test method are the same.
SCOPE
1.1 This test method covers the Calculated Cetane Index formula, which represents a means for directly estimating the ASTM cetane number of distillate fuels from API gravity and mid-boiling point. The index value, as computed from the formula, is termed the Calculated Cetane Index.
1.2 The Calculated Cetane Index is not an optional method for expressing ASTM cetane number. It is a supplementary tool to estimate cetane number when used with due regard for its limitations.
1.3 The Calculated Cetane Index formula is particularly applicable to straight-run fuels, catalytically cracked stocks, and blends of the two.Note 1
This test method is temporarily retained because the proposal to the U.S. EPA to control diesel fuel aromatics concentrations via a 40 Calculated Cetane Index minimum is based on the correlation between Test Method D 976 and aromatics concentration. Test Method D 4737 is the preferred method as estimator of cetane number.
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.

General Information

• Status: Historical
• Publication Date: 30-Nov-2006
• ICS: 75.160.20 - Liquid fuels
• Technical Committee: D02 - Petroleum Products, Liquid Fuels, and Lubricants
• Drafting Committee: D02.E0 - Burner, Diesel and Non-Aviation Gas Turbine Fuels

Relations

• Replaces: ASTM D976-04be1 - Standard Test Methods for Calculated Cetane Index of Distillate Fuels
• Effective Date: 01-Dec-2006
• Referred By: ASTM D7468-22 - Standard Test Method for Cummins ISM Test
• Effective Date: 01-Dec-2006
• Referred By: ASTM D7371-14(2022) - Standard Test Method for Determination of Biodiesel (Fatty Acid Methyl Esters) Content in Diesel Fuel Oil Using Mid Infrared Spectroscopy (FTIR-ATR-PLS Method)
• Effective Date: 01-Dec-2006
• Referred By: ASTM D7422-22 - Standard Test Method for Evaluation of Diesel Engine Oils in T-12 Exhaust Gas Recirculation Diesel Engine
• Effective Date: 01-Dec-2006
• Referred By: ASTM D5967-21 - Standard Test Method for Evaluation of Diesel Engine Oils in T-8 Diesel Engine
• Effective Date: 01-Dec-2006
• Referred By: ASTM D5966-22 - Standard Test Method for Evaluation of Engine Oils for Roller Follower Wear in Light-Duty Diesel Engine
• Effective Date: 01-Dec-2006
• Referred By: ASTM D7467-20a - Standard Specification for Diesel Fuel Oil, Biodiesel Blend (B6 to B20)
• Effective Date: 01-Dec-2006
• Referred By: ASTM D7484-23 - Standard Test Method for Evaluation of Automotive Engine Oils for Valve-Train Wear Performance in Cummins ISB Medium-Duty Diesel Engine
• Effective Date: 01-Dec-2006
• Referred By: ASTM D8048-21ae1 - Standard Test Method for Evaluation of Diesel Engine Oils in T-13 Diesel Engine
• Effective Date: 01-Dec-2006
• Referred By: ASTM D7583-16(2023) - Standard Test Method for John Deere Coolant Cavitation Test
• Effective Date: 01-Dec-2006
• Referred By: ASTM D7156-19 - Standard Test Method for Evaluation of Diesel Engine Oils in the T-11 Exhaust Gas Recirculation Diesel Engine
• Effective Date: 01-Dec-2006
• Referred By: ASTM D6923-23 - Standard Test Method for Evaluation of Engine Oils in a High Speed, Single-Cylinder Diesel Engine—Caterpillar 1R Test Procedure
• Effective Date: 01-Dec-2006
• Referred By: ASTM D7549-23 - Standard Test Method for Evaluation of Heavy-Duty Engine Oils under High Output Conditions—Caterpillar C13 Test Procedure
• Effective Date: 01-Dec-2006
• Referred By: ASTM D8074-22 - Standard Test Method for Evaluation of Diesel Engine Oils in DD13 Diesel Engine
• Effective Date: 01-Dec-2006
• Referred By: ASTM D6751-23a - Standard Specification for Biodiesel Fuel Blendstock (B100) for Middle Distillate Fuels
• Effective Date: 01-Dec-2006

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation:D976–06
Standard Test Method for
1
Calculated Cetane Index of Distillate Fuels
This standard is issued under the fixed designation D976; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope* D287 Test Method forAPI Gravity of Crude Petroleum and
Petroleum Products (Hydrometer Method)
1.1 This test method covers the Calculated Cetane Index
D613 Test Method for Cetane Number of Diesel Fuel Oil
formula, which represents a means for directly estimating the
D1298 Test Method for Density, Relative Density (Specific
ASTM cetane number of distillate fuels from API gravity and
Gravity), or API Gravity of Crude Petroleum and Liquid
mid-boiling point. The index value, as computed from the
2 Petroleum Products by Hydrometer Method
formula, is termed the Calculated Cetane Index.
D2887 Test Method for Boiling Range Distribution of
1.2 The Calculated Cetane Index is not an optional method
Petroleum Fractions by Gas Chromatography
forexpressingASTMcetanenumber.Itisasupplementarytool
D4052 Test Method for Density, Relative Density, and API
to estimate cetane number when used with due regard for its
Gravity of Liquids by Digital Density Meter
limitations.
D4737 Test Method for Calculated Cetane Index by Four
1.3 The Calculated Cetane Index formula is particularly
Variable Equation
applicable to straight-run fuels, catalytically cracked stocks,
4
2.2 ASTM Adjuncts:
and blends of the two.
Nomograph for Calculated Cetane Index
NOTE 1—This test method is temporarily retained because the proposal
to the U.S. EPA to control diesel fuel aromatics concentrations via a 40
3. Significance and Use
Calculated Cetane Index minimum is based on the correlation between
3.1 The Calculated Cetane Index is one tool available for
TestMethodD976andaromaticsconcentration.TestMethodD4737isthe
estimating ASTM cetane number where a test engine is not
preferred method as estimator of cetane number.
available for determining this property. It may be employed for
1.4 This standard does not purport to address all of the
approximating cetane number where the quantity of sample is
safety concerns, if any, associated with its use. It is the
too small for an engine rating. In cases where the cetane
responsibility of the user of this standard to establish appro-
number of a fuel has been initially established, the index is
priate safety and health practices and determine the applica-
useful as a cetane number check on subsequent samples of that
bility of regulatory limitations prior to use.
fuel, provided its source and mode of manufacture remain
unchanged.
2. Referenced Documents
3.2 Test Method D4737 may also be used to approximate
3
2.1 ASTM Standards:
the ASTM cetane number of diesel fuels.
D86 Test Method for Distillation of Petroleum Products at
3.2.1 ProcedureAof Test Method D4737 was developed as
Atmospheric Pressure
a result of a larger degree of offset between Test Method D976
Cetane Index and the results of Test Method D613 over the
entirerangeofthecorrelation.Generally,ithasbeenfoundthat
1
This test method is under the jurisdiction of ASTM Committee D02 on
use ofTest Method D4737 results in less offset than use ofTest
Petroleum Products and Lubricants and is the direct responsibility of Subcommittee
Method D976, but there can be specific cases where this is not
D02.E0 on Burner, Diesel, Non-Aviation Gas Turbine, and Marine Fuels.
true.
Current edition approved Dec. 1, 2006. Published January 2007. Originally
´1
approved in 1966. Last previous edition approved in 2004 as D976–04b . DOI: 3.2.2 Procedure A of Test Method D4737 is recommended
10.1520/D0976-06.
to estimate the cetane number of diesel fuels with sulfur
2
A method of calculating cetane index was developed by the Diesel Fuels
contents above 500 ppm or No. 1–D diesel fuels.
Division, Coordinating Fuel and Equipment Research Committee of the Coordinat-
3.2.3 Procedure B of Test Method D4737 is recommended
ing Research Council. SeeYoung, H. D., “Methods for Estimating Cetane Number,”
Proceedings, PPIRA, American Petroleum Institute, Vol. 30 M [III], 1950. This
to estimate the cetane number of No. 2–D diesel fuels with
method was revised in 1960 by Research Division I of Committee D02 to conform
sulfur contents at or below 500 ppm.
to the revised Test Method D613.
3
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
4
Standards volume information, refer to the standard’s Document Summary page on
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