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.





PolyGUARD All Season High Performance Motor OIl 5W-30, API SG/CD

PolyGuard Products Division, Medina, MN


Purchased in: Speedy Q,  New Baltimore, MI

Date of purchase: 8/27/2012

Whereas the results of the tests conducted on this sample meet the requirements for an SAE 5W-30 engine oil, it cannot be determined if it meets API SG/CD since these specifications are obsolete.

Advisory: This product is labeled as meeting API SG/CD which is an obsolete specification and is not recommended for passenger cars built after 1993. In addition, this product is labeled as meeting API CD which is also an obsolete specification. The product label does not adequately warn consumers of this limited use. Click here for API Service Categories






PHYSICAL TESTS Standard/ranges-b Average-e
 TBN, mg KOH/g, (ASTM D2896) 6.1 to 8.3 7.2 4.8
 Viscosity @ 100ºC, cSt, (ASTM D445) 9.3 to 12.5 10.5 10.6
 Viscosity @ 40ºC, cSt, ASTM D445 55.8 to 65.2 61.88 61.4
 Viscosity Index (ASTM D2270) 156 to 169 160 165
 Viscosity @ -30ºC mPa s (cP) (ASTM D5293) 6,600 Max 5,775 3,903
 Volatility, mass % loss, 1 hr, @ 250ºC (ASTM D5800) n/a 14.2 18.9
    Nitrogen μg/g (ASTM D-5762) 599 to 990 804.2 n/r
    Calcium 1,570 to 2,460 2,051 1,549
    Magnesium, ppm 6 to 46 12.3 5
    Phosphorus,  ppm n/a 703 474
    Zinc, ppm 766 to 868 791 551
    Molybdenum,  ppm <1 to 269 60 47
    Barium, ppm <1 <1 <1
    Boron,  ppm <1 to 237 79 9
    Silicon,  ppm-d 3 to 9 5 3
    Potassium, ppm 9 to 17 11 <5
    Manganese, ppm <1 <1 <1
    Titanium, ppm <1 to 114 11 <1
    Sulfur, ppm 5,000 Max 2,785 n/r
    Copper, ppm <1 <1 <1
    Sodium, ppm 5 to 454 172 <5
    Vanadium, ppm <1 <1 <1
    Silver, ppm <1 <1 <1
    Aluminum, ppm <1 to 3 1 1
    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 yellow 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.



The American Petroleum Institute sets forth a number of laboratory and engine tests required to meet their performance specification. Although laboratory tests alone cannot be used to establish if an engine oil meets API specifications they can be used to determine if it doesn't.



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 more on chart and Viscosity @ -30șC