Blotter Spot Test Procedure

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Jul 1, 2017
Venezuela, South America
I want to start perfoming blotter spot tests every 500 miles to see how the oil is perfoming on my car, I know that this kind of test can´t replace a UOA but I want to start getting used to this kind of test so I can know when a specific oil brand is performing worse than others. What procedure should I use? Can I use printer paper or should I use a thicker paper? Should I perform the test when the engine is at operating temp or cold? I want to learn how to do this test in as accurately as I can.
buy a premade test - they are cheap and use tested paper. If you don't do this comparisons will be meaningless unless you use the exact same paper and light sources every test. You could use a stack of the same business cards I always did it hot per the instructions in the kits - they being the debris kept in suspense will tend to fall out making a cold sample look better than a hot one. how much it matters - hard to say. UD
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I've played around with business cards, newsprint and A4 size letter head paper and 70gm printing paper. Currently settle at printing paper, 80 gm would work as well I suppose. I did it hot(after more than 30 minutes drive) , as the blotter 'spreads' better and starting off at say 5000 km,followed by every other 1500/2000 km interval frequencies. Check out on some reading sites here from members within the thread. Blotter spot test is free and easy. It helps me in qualitative aspect.
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With my last car I used a pack of perforated sheets of blank business cards for printers. Tore off a new card every time I took a sample. After the sample set up, I wrote the date the mileage and the oil/filter combination on the card. Then they went in a binder with plastic business card pages so I could compare over time and test extending OCIs. I may start doing the cards again once the Buick's out of factory warranty next year and the Honda's oil consumption TSB expires at 125k miles. Right now, I just check the levels once a month and call it good.
Originally Posted By: Donald
White coffee filter
I did not like it when I tried them (the red circle is a drop of fresh oil to compare to). and 3 days later:
Originally Posted By: Char Baby
I've always heard here at Bob's that, 3x5 index cards were ideal.
That is what I use now. I had tried business cards, but some cards have a funny coating on them, and a pack of 3x5 cards is cheap and leave space to write info on it if you want too.
This are the results using 75 g/m2 printing paper, I took the sample 15 minutes after the engine was shutdown at operating temp, I let the drop dry for 2 days. The oil is 1725 miles old by the way. What do you think about using this kind of paper? Could a different paper give me better results?
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