I've had this F-150 for about a year now and I've had the same fill in there the whole time.
It has only been about 4,000 miles in the past year, but It does regularly get up to temp. With it being 102 in the afternoons it doesn't take much. And with me going up and down highways when I do drive it I believe the oil is doing fine.
I planned on going 7,000 miles on this OCI. However I am kind of bored with it. The Lifter tick is still there, although the oil is BLACK. And from what I can see using a flashlight to look at the lifters on the drivers side the engine is EXTREMELY clean. No sludge and very little if any varnish.
Like I was saying. I got bored and realizing that I am now a quart low on the dipstick I decided to add a quart of MMO.
I will take it out on a drive tonight and see how it does.
I'm thinking it might take me another 6 months to rack up the 3,000 miles to make this a 7,000 mile OCI. But I plan on doing a UOA and posting it when I am done.