(Did a search and couldn't find any such topic for this engine.) I'm planning to break in my new 4.6-litre on Motorcraft 5W-20 semi-synthetic (and import that oil into Canada if I can't find proof that the Cdn Motorcraft 5-20 is semi-syn, which the bottle says nothing about). I'd do that for 10,000 to 15,000 km or so, then switch to fully synthetic. I'm sure tempted to go off-grade for oil this good. Also, the "0" in 0W-30 ought to be great for cold starts in our Ottawa winters. Anybody actually have experience with this oil in the newer 4.6s?