mf150, where you live it never gets cold or hot, just foggy
![[Big Grin]](images/icons/grin.gif)
. So either the Mobil 1 10W-30 or the 5W-30 would be fine. The only thing I can add to this is that your new 4.6L Ford engine being an OHC instead of pushrods is "tighter" and the top end could benefit from the faster oil flow at start up with the 5W-30. Also if you are going to change your oil at 3,000-5,000 mile intervals, as you stated previously, I don't think you have to worry about the 5W-30 "breaking" down faster than the 10W-30.
Whimsey