Hi guys, I have a 2011 BMW 535i, in which I have been using Pentosin Pento High Performance 5W-30 oil and Hengst oil filters since I bought it. This time, I tried Ravenol Ravenol FullSynth Turbo VST 5W-40 oil (and another Hengst filter). Now I’ve done 3 oil changes with the Pentosin, but this time, I noticed the engine is so much quieter idling. I know it could be a placebo, but I don’t remember it sounding this smooth with the Pentosin oil. So far, engine sounds the best it has ever sounded.