We all know that oil from the canister darks right after adding to the engine. Firstly, due to detergents in the oil, and secondly, due to decomposition caused by heating of components (oxidation).
In our experiment, the color began to change dramatically after 30 minutes of heating, and already after 2 hours of heating became too dark to be able to see anything through it. However, we noticed such thing: a dark oil becomes transparent when we set the camera to the night mode - turns on IR LED and the camera itself begins to perceive the invisible part of the spectrum. And here is where the fun begins: the transparency of oil in the infrared light varies depending on the degree of roasting. And in some oils it changes almost immediately, while in others only at the end of tests. From the lightest to the darkest: 1 MOTUL - 2 G-Energy - 3 Castrol M - 4 Mobil - 5 Total - 6 Genesis A - 7 Genesis C - 8 Shell - 9 Castrol E - 10 Idemitsu. What causes this and what is it - is difficult to say, the question requires an examination.
Dear readers, how would you explain this change of color? If you have a relationship to OilClub and similar resources - put the information out there, maybe someone have any ideas.