Can anyone familiar with the blotter test method help me understand, why the drops of Ravenol and Eneos look so different? Also, what could have made the Eneos (picture 2.) so dirty so quickly?
Car: 2006 Saab 9-3 1.9 Tdi 110kW.
Have been changing oil approx. every 10000km, recent five changes have been Ravenol VSI 5w40 and a most recent two Ravenol VMO 5w40. Now changed oil to Eneos Premium Hyper 5W40.
Just after changing to Eneos I also did some repair work with engine and intake: Changed glow plugs, thermostat, removed EGR, DPF and the swirl flaps from the intake manifold (also cleaned it, as it was very dirty), removed them also from the ECU and did a custom Chiptuning (approx 140kW now). After this I tested the car with some 30...40 hard accelerations.
Then, after testing, with some 500km on the fresh Eneos I did the blotter test (2. on the picture) and I was confused how dirty it was and how different it looked compared to a classic view of a blotter test (1. on the picture). Did several blotter test between 500-1500km and nothing changed. Then I changed the oil once more to get some peace of mind, Eneos again, and after that the blotter tests from 0km to 1500km (3. on the picture) have looked practically the same - nice and clean.
1) Last fill of Ravenol before the change to Eneos (1500km on the oil on this image) - Ravenol on my petrol car looks practically the same, just the inner circle is not that dark.
2) First fill of Eneos after 1500km (500km drop looked exactly the same) - so dirty and what does this second darker circle mean (marked with red lines)?
3) After the 1500km blotter I changed the oil and filter again to fresh Eneos - this is what it looked like after the change and now after 1500km on it. A lot cleaner, but also has this second darker ring starting to form?
So the questions:
a) Does Eneos have way better cleaning properties than Ravenol and therefore cleaned some deposits from the engine?
b) Did the physical work of removing the EGR and swirl flaps etc. leave a lot of dirt/deposits into the engine?
c) Did those 40 hard accelerations do something - cleaned some deposits from the turbo?
d) Why do Eneos drops look different than Ravenol which has a classic view with one darker inner circle? Can Ravenol hold deposits better according to these test (all deposits in this inner circle and more "fresh/clean" oil around)?
e) Is it OK to use this Eneos oil or should I switch back to Ravenol?
Sorry for my long post. I know these tests are quite stupid, but they do show you changes in oil if done regularly... Also i know that I should not worry at all when changing oil every 10000km (20000km being the manufacturer recommendation)... and not bother with those blotter test at all... but as I have bothered I would like some help with interpreting these.