I just had my oil changed with Mobil 1 0w-40 and its running really quiet and smooth. I've been using Mobil 1 5w30 HM and 10w30 HM, which are thick 30's, they worked fine, but it seems to be smoother on the 0w-40.
It still feels just as peppy as before. If I can keep finding the 0w-40 on sale, I'll keep using it. I bought 5 quarts with Mobil 1 filter at Auto Zone for 30 bucks.