Test Method-The data obtained from the use of this test method provide a comparative index of the fuel-saving capabilities of automotive engine oils under repeatable laboratory conditions. A baseline calibration oil (hereafter referred to as BC oil) has been established for this test to provide a standard against which all other oils can be compared. The BC oil is an SAE 5W-30 grade fully formulated lubricant. There is a direct correlation of Test Method D6837 (Sequence VIB) Fuel Economy Improvement (FEI) by percent with the fuel economy results obtained from vehicles representative of current production running under the current EPA testing cycles. The test procedure was not designed to give a precise estimate of the difference between two test oils without adequate replication. Rather, it was developed to compare a test oil to BC oil. Companion test methods used to evaluate engine oil performance for specification requirements are discussed in the latest revision of Specification D4485.

Use-The Sequence VIB test method is useful for engine oil fuel economy specification acceptance. It is used in specifications and classifications of engine lubricating oils, such as the following:

Specification D4485.

API Publication 1509.

SAE Classification J304.

SAE Classification J1423.

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1.1 This test method covers an engine test procedure for the measurement of the effects of automotive engine oils on the fuel economy of passenger cars and light-duty trucks with gross vehicle weight of 3856 kg or less. The tests are conducted on a dynamometer test stand using a specified spark-ignition engine with a displacement of 4.6-L. It applies to multiviscosity grade oils used in these applications.

1.2 This test method also provides for the running of an abbreviated length test that is referred to as the VIBSJ. The procedure for VIBSJ is identical to the Sequence VIB with the exception of the items specifically listed in Annex A13. The procedure modifications listed in Annex A13 refer to the corresponding section of the Sequence VIB test method.

1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.3.1 Exceptions-Where there is no direct SI equivalent such as screw threads, National Pipe Threads/diameters, tubing size, or single source supply equipment specifications. Brake Specific Fuel Consumption is measured in kilograms per kilowatthour. In Figs. A2.4, A2.5, and A2.8, inch-pound units are to be regarded as standard.

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 and health practices and determine the applicability of regulatory limitations prior to use.