Yesterday I took my W212 E220 Bluetec in for service. I always take my own oil with me (Mobil 1 ESP 5w30). The mechanic told me that he also added an oil additive to the oil for "better protection". I really don't like oil additives in my oil. I believe that it will mess with the oil formulation. The additive he used is the Nano-Motorinnenversiegelung FÖRCH https://www.foerch.de/product/0a814...75eba992/nano-motorinnenversiegelung-foerch-5. I have never heard of this company. Do you think it would be a waste to change the oil again?