Mobil1 15w50 here and never any issues. If you saw what my crank and bearings looked like after 11k miles of the torture I put my motor through you will think twice before calling it crap. For one the 15w50 didnt get the low standards that the other oils got. Matter fact when they tested even the old formula 15w50 it passed with flying colors. The lower viscosity oils failed, they have since redone their formula and from what ive seen have passed all testing. Hence the 2 dollar increase/qt that they added to the oil, lol. But again after seeing the results in my own motor, im sticking with mobil1 15w50 and would recommend it to anyone. I also run the mobil1 filter as well.