Hi, I have a question for you, dear colleagues. For most cars, the specification ACEA A5/B5 ILSAC GF-4/5 is recommended. Example of LEXUS, TOYOTA. How the use of oil of the same viscosity, but in the A3/B3/B3/B4 specification, affects wear and engine protection? There is a theory that A5/B5 light running oils cause less high-temperature deposits, lacquers and deposits, especially on the rings. On the other hand, others say and write that the use of A3/B3 oil in LEXUS GS for example causes a smaller amount of so called shavings. Has anyone investigated this topic and whether it is better to take into account the specification e. g. ILSAC GF-4/5 etc. or the most important is the oil film strength, which is higher in A3/B3 oils? I am not talking about ecology but about cleanliness of the engine, amount of deposits and resistance to wear and tear. Please let me know. Thank you.