there is always a lot of different opinions on oil. I use Liqui Moly. Motul is good. Castrol Edge OE Professional is supposedly made in Germany, but Castrol Edge is made in the US. That makes a difference to me, as Europe has very different requirments for their oil than the US does. My dealer reps strongly recommend the Liqui Moly. My understanding is that Mobil 1 used to have very well made synthetic oil, but after they lost a lawsuit against another manufacturer they really dropped their standards. They sued another company for calling their oil a true or 100% synthetic because it did not use enough real synthetic properties in it. The US Courts dropped the suit so Mobil and other US manufacturers had to do the same in order to compete price wise. Oil made in Europe still has to meet much stronger requirments. Anyway, that is what I was told. I have found that it is virtually impossible to find the real truth or the real properties of anyone’s oil, it is kept as a big secret, but I have read that synthetic oil made in Europe is a better oil than US oil in many places. For the extra few dollars, it is worth it to me to put the better oil in my Audi. I also change it every 5k.