Petroleum Quality Institute of America

The Petroleum Quality Institute of America (PQIA) is an independent resource for information and insights on the quality and performance of lubricants in the marketplace.  Our mission is to serve the consumer of lubricants by reporting on the quality and integrity of lubricants in themarketplace.

 

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STP Motor Oil, API SM, ILSAC GF-4, SAE 5W-30

Distributed by J.D. Street & Co., Inc., Maryland Heights, MO

 

Purchased in: Dollar General Store, Holly Springs, MS

Date of purchase: 10-5-2011

 

 

 

 

 

All tests conducted on this sample meet the specifications for API SM and

ILSAC GF-4, SAE 5W-30 Engine oil.

 

 

 

 

 

 

 

 

The ranges and averages shown in the table below are for current specifications (API SN GF-5).

 

PETROLEUM QUALITY INSTITUTE OF AMERICA

TEST PROGRAM
PHYSICAL TESTS Standard/ranges-b Average-e   STP
 TBN, mg KOH/g, (ASTM D2896) 6.1 to 8.3 7.2   8.4
 Viscosity @ 100ºC, cSt, (ASTM D445) 9.3 to 12.5 10.5   11.0
 Viscosity @ 40ºC, cSt, ASTM D445 55.8 to 65.2 61.88   65.86
 Viscosity Index (ASTM D2270) 156 to 169 160   159
 Viscosity @ -30ºC mPa s (cP) (ASTM D5293) 6,600 Max 5,775   5,820
 Volatility, mass % loss, 1 hr, @ 250ºC (ASTM D5800) 15 Max 14.2   12.5
ELEMENTAL ANALYSIS-c      
Additives
    Nitrogen μg/g (ASTM D-5762) 599 to 990 804.2  889.6
    Calcium  1,570 to 2,460 2,051   2,137
    Magnesium, ppm  6 to 46 12.3   9
    Phosphorus,  ppm 600 to 800 703   722
    Zinc, ppm  766 to 868 791   772
    Molybdenum,  ppm  <1 to 269 60   82
    Barium, ppm  <1 <1   <1
 
    Boron,  ppm  <1 to 237 79   227
    Silicon,  ppm-d  3 to 9 5   5
    Potassium, ppm 9 to 17 11   10
    Manganese, ppm  <1 <1   <1
    Titanium, ppm  <1 to 114 11   <1
    Sulfur, ppm  5,000 max 2,785   3,075
    Copper, ppm  <1  <1   <1
    Sodium, ppm  5 to 454 172   <5
    Vanadium, ppm  <1 <1   <1
Contaminants
    Silver, ppm  <1 <1   <1
    Aluminum, ppm  <1 to 3 1   2
    Chromium, ppm  <1 <1   <1
    Iron, ppm  <1 to 1 1   <1
    Nickel, ppm  <1 <1   <1
    Lead, ppm  <1 <1   <1
    Antimony, ppm  <1 <1   <1
    Tin, ppm  <1 <1   <1

a- Click here for product label.

b- Standards, shown in orange, are established by API, SAE and others. Ranges, shown in teal, represent the high and low data for the 13 major brands of API SN ILSAC GF-5 tested in September 2011.

c-Test Method for metal analysis is ASTM ASTM D5185.

d- Although silicon is used as an antifoam additive in lubricants, concentrations above 7ppm have been linked to contamination from abrasive material,

e- Average of the 13 major brands of API SN ILSAC GF-5 tested in September 2011.

 

  
STP 5W-30
The American Petroleum Institute sets forth a number of laboratory and engine tests required to meet an API SN ILSAC GF-5  performance specification. Although laboratory tests alone cannot be used to establish if an engine oil meets API SN, they can be used to determine if it doesn't.

The following is a comparison of the test results for the sample of STP 5W-30 tested with the API SN ILSAC GF-5 requirements.

 
Viscometrics

The viscometrics meet the required targets for a 5W-30.

Viscosity @ 100șC, cSt, (ASTM D445)
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  Viscosity @ -30șC mPa s (cP) (ASTM D5293)
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Click here for more on chart and Viscosity@100șC,cSt                Click here for about chart and Viscosity @ -30șC

 
   
Volatility Phosphorus
The volatility meets the requirements for an API SN ILSAC GF-5 designation.
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  The phosphorus content meets the requirements
for an API SN ILSAC GF-5 designation.
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Click here for more on chart and Volatilty Click here for more on chart and phosphorus
 

  
FRONT AND BACK LABELS FROM PRODUCT TESTED