i have a 2009 f150 with the 5.4L and almost 100k miles. It is spec'd for 5w20. I recently changed the oil to TGMO 0w20 for the winter and it has had a great deal of cam phaser/timing chain noise ever since. Today,after driving for a couple of hours, I went to back up and the phaser noise got very loud and the idle got rough. I immediately shut it off and restarted and it idled normally. I went and changed the oil out for some 5w30 edge titanium. I drove another couple of hours after and the phasers were much quieter and no recurance of the stumbling. The TGMO was like water while draining it. Maybe the age of the engine no longer lends itself to very thin oils.