Originally Posted By: KenO
The 5W-30 will be fine, but it calls for 5W-20. You won't damage anything. They recommend 5W-50 for the 'track pack' car, and really the only functional difference is an oil cooler, in regards to the engine.
Ummmmm no.
The track pack engine is more different than just the oil cooler.
Just off the top of my head there are piston squirters on the track pack variety,which can superheat the oil when enjoying those horses,which from what I've read from ford is the most significant reason for the 5w-50 specification.
Without those piston squirters the oil wouldn't hear up nearly as fast.
Tuning is significantly different as well.
And whether 5w-20 or 5w-50 is being used in a mod 5.0 none if the "electronics" are affected,contrary to the comment above.
I laugh at these absurd beliefs that running thicker oil will in some way affect an engines ability to run solely based on rumour.
I've run 20 grades and 40 grades in engines with cylinder deactivation and vvt and the difference in how the engine runs is not perceptible.
Think about it. All those gizmos work just fine when the engine is cold,so let's get real here. A 20 grade cold is a whole lot thicker than a 40 or 50 grade hot,and all the systems run just fine in the cold 20 grade,so what kind of foolish reasoning can we come up with to convince anyone with a brain that running an oil thicker than specified(within reason)will negatively impact or damage an engine.
Laughable.