How long can an oil sample sit before analysis?

[televascular]

I have an air-tight plastic vial containing motor oil I have been meaning to get analyzed, but never got around to sending out. It's been about three months since I collected the sample. If I send it now, will the analysis be accurate? Perhaps fuel has evaporated, providing an inaccurate fuel dilution reading?

I am switching brands next OCI, so I would really like a comparative UOA.

 

[Camu Mahubah]

It took me three weeks before I had time/money to send in mine.

 

[benjamming]

It should be fine since it has been sealed. What lab will you be using? If Blackstone, you'll get a false fuel reading anyway so it won't matter.

 

[BradC]

So are you saying that Blackstone's fuel dilution tests leave something to be desired?

 

[Gary Allan]

Hmm... I don't know if you can say that. B-S calculates the fuel dilution from the flash point ..but uses a different process ..hence get a different number than Terry with the closed cup method. I didn't see that it established that B-S's method was "wrong". If plotted, their's too should form a straight line ..since they're merely calculating % based on flash. If the table their using is not inherently flawed ..then it should have a like contour.

..back on topic..

The consensus of rhetoric that I've heard when this question has been asked before is that as long as it's not exposed to air or light ..then it should be fine. I imagine that the light precaution is for UV altering the sample.