SwRI: Sequence VIB (ASTM D 6837) Test for ILSAC GF-3

  image of the Sequence VIB test in progress at SwRI. This test measures the effects of automotive engine oils on the fuel economy of passenger cars and light-duty trucks equipped with a low-friction engine
 

The Sequence VIB test at SwRI measures the effects of automotive engine oils on the fuel economy of passenger cars and light-duty trucks equipped with a low-friction engine.

The Sequence VIB (ASTM D 6837) procedure measures the effects of automotive engine oils on the fuel economy of passenger cars and light-duty (3,856 kg, 8,500 lb or less gross vehicle weight) trucks equipped with a low-friction engine.


Specifications include:

  • ILSAC GF-3

  • ILSAC GF-4

  • API Category SL

  • API Category SM

Sequence VIB Test Equipment and Procedure

The Sequence VIB test uses a 1993 4.6-liter Ford modular V-8 gasoline engine equipped with an external oil heating/cooling system and a flying flush system for changing oil without an engine shutdown.


Fuel consumption is measured at each of 5 speed, load, and temperature test conditions for an SAE 5W-30 baseline oil (BC). The candidate oil is introduced and aged for 16 hours at Aging Phase I conditions, and fuel consumption is measured for each of the five test conditions.


For Aging Phase II conditions, the candidate oil remains in the engine and is aged for 80 hours. Fuel consumption is measured for each of the five test conditions, followed by a repeat of the BC oil at the five test conditions.

 

Conditions

Aging Stages

Test Stages

Phase I

Phase II

1

2

3

4

5

 Speed, rpm

1,500

2,250

1,500

800

800

1,500

1,500

 Normal power, kW

15.39

23.10

15.39

2.18

2.18

15.39

15.39

 Oil temp, °C

125

135

125

105

70

70

45

 Coolant temp, °C

105

105

105

95

60

60

45

 

Sequence VIB Test Results

At the end of the test, results are expressed as a percentage of change in kg of fuel consumed for the candidate oil after Aging Phase I and Aging Phase II compared to the BC before and after candidate oil. New oil and oil after Aging Phase II viscosity at 40 °C and 100 °C are required.


Fuel economy improvement, which equates to the fuel economy results obtained from vehicles representative of current production vehicles running under the current U.S. Environmental Protection Agency (EPA) testing cycles, is calculated by the following formula where units for BSFC are kg/kWh:

 

Stage

Actual (kg/kWh)

Normal
Power
(kW)

Time
Factor (H)

Fuel Consumed
(kg)

1

BSFC

x

15.39

 x

0.0802

 =  

2

BSFC

x

2.18

 x

0.0787

 =  

3

BSFC

x

5.81

 x

0.0848

 =  

4

BSFC

x

15.39

 x

0.0864

 =  

5

BSFC

x

15.39

 x

0.0699

 =  

  Total mass fuel consumption for all five stages =                            


The following results are computed:

  • Total fuel consumed, as shown above for the BC oil

  • Candidate oil test stages after aging Phase I

  • Candidate oil test stages after aging Phase II

  • BC oil after candidate

The test oil fuel economy improvement (%FEI) is computed as follows:
 

%FEI Test Oil Phase I =

{[(BC before × 80%)
+ (BC after × 20%) 
– Test oil phase I]/[(BC before × 80%)
+ (BC after × 20%)]} × 100

%FEI Test Oil Phase II =

{[(BC before × 10%) 
+ (BC after × 90%) 
– Test oil phase II]/[(BC before × 10%)
+ (BC after × 90%)]} × 100
 

Sequence VIB Pass / Fail Criteria

Pass/fail criteria for ILSAC GF-3 and API SL (minimum %FEI versus ASTM BC):

  • SAE 0W-20 and 5W-20 viscosity grades:

    • 2.0% min. after 16 hours aging (Phase I FEI)

    • 1.7% min. after 96 hours aging (Phase II FEI)

  • SAE 0W-30 and 5W-30 viscosity grades:

    • 1.6% min. after 16 hours aging (Phase I FEI)

    • 1.3% min. after 96 hours aging (Phase II FEI)

    • 3.0% FEI + FEI2

  • All other SAE multiviscosity grades:

    • 0.9% min. after 16 hours aging (Phase I FEI)

    • 0.6% min. after 96 hours aging (Phase II FEI)

    • 1.6% FEI1 + FEI2

Pass/fail criteria for ILSAC GF-4 and API SM (minimum %FEI versus ASTM BC)

  • SAE 0W-20 and 5W-20 viscosity grades:

    • 2.3% min. after 16 hours aging (Phase I FEI)

    • 2.0% min. after 96 hours aging (Phase II FEI)

  • SAE 0W-30 and 5W-30 viscosity grades:

    • 1.8% min. after 16 hours aging (Phase I FEI)

    • 1.5% min. after 96 hours aging (Phase II FEI)

  • All other SAE viscosity grades:

    • 1.1% min. after 16 hours aging (Phase I FEI)

    • 0.8% min. after 96 hours aging (Phase II FEI)

For more information about the Sequence VIB (ASTM D 6837) procedure capabilities at Southwest Research Institute (SwRI) or how you can contract with SwRI, please contact Guy Stubbs at gstubbs@swri.org or (210) 522-5039.

©1998-2009 Copyright Southwest Research Institute
Printed from:
http://www.swri.org/4org/d08/GasTests/VIBtest/default.htm?
Southwest Research Institute® (SwRI®) is an independent, nonprofit, applied engineering and physical sciences research and development organization with 12 technical divisions using multidisciplinary approaches to problem solving. The Institute occupies more than 1,200 acres and provides nearly two million square feet of laboratories, test facilities, workshops, and offices for more than 3,300 employees who perform contract work for industry and government clients.