I would suggest you deal with your lab as to what may be acceptable. You could also find limits in ASTM D4304 available at http://www.astm.org/Standards/D4304.htm.

mineral oils may have a density of say somewhere between 0.85 and 0.95 kg/l, depending on their composition. more viscous oils tend to have a higher density.

that you find a discrepancy between the values in the manufacturers spec and what a lab reports is not unusual, because there can be several reasons for that. to start with: the value that is documented in sales literature not necessarily is measured on the oil delivered to you. it may well be measured several years ago, either as a one off measurement or calculated as a average value based on several measurements of various batches. in product literature the usual phrasing most times is something alike "average/typical values that may be expected".

the value you get from a lab is a real measurement from the sample you supplied - depending on the type of analysis carried out it may well be a average as well because in a lot of standards it is stipulated that the measurement should be carried out several times to reduce the risk of errors due to reproducibility.

a third variation may well be due to the blending accuracy in the lubricant plant. when you want to mix a ISO 220 gear oil for example, the viscosity at 40 degrees C should be between 198 and 242 mm2/s - the nominal value of 220 plus or minus 10%. for normal lubrication requirements that is more then sufficiently close, but when the density would be measured from the extremes that are within the spec the densities will differ.

tanks a lot dears

bur how about synthetic specially refrigerant oil?
if we have a 0.2 different in density between data sheet and lab report for fresh oil is it acceptable?.which astm code refer to specification of refrigerant oils.

best regard