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.







City Star 10W40, API SA


Purchased in: Toledo Food Mart, Toledo, Ohio

Date of purchase: 8-26-2012



CONSUMER ALERT:  The product tested shows an oil that will cause harm to a car engine.


The label on this product states "10W40 Motor Oil." Test results show this product is not an SAE 10W-40, and does not meet any recognized specifications for motor oil.   The viscosity for this oil is close to 80% below where it should be for a SAE 10W-40. Also of high concern is that the sample of City Star tested has in excess of 1,000 parts per million of silicon. Such levels are unheard of in engine oils and strongly suggest the sample is highly contaminated.


To consumer's who likely don't relate to what viscosity means, if you see this brand on the shelf at a convenience store, shake the bottle; it will sound like water in a bottle. 



Further, this product is labeled as meeting API SA which is an obsolete specification. The API cautions this specification "Contains no additives. Not suitable for use in gasoline-powered automotive engines built after 1930. Use in more modern engines may cause unsatisfactory performance or equipment harm." The product label does not adequately warn consumers of this limited use. Click here for API Service Categories.

Note: Although the sample of City Star engine oil tested was purchased in Toldeo, Ohio, this brand was observed in other locations in and around the state. Please contact  PQIA at with the store name and location if you see this brand on the shelves.








Test Results

Standards, shown in orange, are established by API, SAE and others.
 TBN, mg KOH/g, (ASTM D2896)     0.49
 Viscosity @ 100ºC, cSt, (ASTM D445) 12.5 to 16.3   2.6
 Viscosity @ 40ºC, cSt, ASTM D445     10.0
 Viscosity Index (ASTM D2270)      
 Viscosity @ -25ºC mPa s (cP) (ASTM D5293) 7,000 Max   394
    Calcium     1
    Magnesium, ppm     1
    Phosphorus,  ppm     13
    Zinc, ppm 1
    Molybdenum,  ppm     0
    Barium, ppm 0
    Boron,  ppm     0
    Silicon,  ppm     >1000
    Potassium, ppm     <1
    Manganese, ppm     <1
    Titanium, ppm     <1
    Copper, ppm     <1
    Sodium, ppm     5
    Vanadium, ppm     <1
    Silver, ppm     <1
    Aluminum, ppm     <1
    Chromium, ppm     <1
    Iron, ppm     1
    Nickel, ppm     <1
    Lead, ppm     <1
    Antimony, ppm     <1
    Tin, ppm     <1


City Star 10W-40, API SA

The viscometrics of City Star do not meet the required targets for a 10W-40.

Viscosity @ 100șC, cSt, (ASTM D445)
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 Viscosity @ -25șC 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