5w-30

I have been researching this topic for a couple weeks. Combing through threads here -- I very much appreciate the data, but I can't find a situation that necessarily fits. I have an extended 8 year 80k mile warranty on this car that is "new to me" which I purchased with about 21k miles on it...

I'm new to the forum... not really sure how to introduce myself... so... Hey. How's it goin'? I'm down to my last jug of Rotella Gas Truck 5W30 and need to change the oil in my F150 soon. It has an iron block 4.6L. Under 25K miles on it. I broke it in on Valvoline conventional 5W30, then...