Thoughts on break-in and 1st oil change,
 

Bought a 5L LARIAT with the 10speed transmission and have been driving it gently for the first 500 miles per the dealer's recommendations. Took it for a 2-day cruise through the Pennsylvania mountains, so lots of up, down, fast, medium & slow speeds and lots of shifting. No issues yet.at 1000 miles.

So should I floor it a bit yet or continue on driving like my grandmother for a while yet? And what about 1st oil change? Probably too early but when is reasonable?

I just underwent a new engine replacement due to excessive oil consumption. Burned oil from 1,500 miles to 29,000 before the TSB from Ford popped up. I’m at 700 miles on the new engine, and haven’t noticed the dipstick short on the slippery yet. The dealer said Ford no longer recommends varying speed. “Just be easy on it” was the response I received. Hmmmm. I was also told changing the first oil change before 5,000 was not needed. Hmmmmm. I normally drop it by 1,500, and 3,500 every change thereafter.

Just keep in mind that there are thousands of work trucks out there that get loaded down with a thousand pounds of payload, hooked up to a trailer and off to work it goes.

Just drive it.
DO NOT follow random advice from the dealership. The truck came with an owners manual. Open it. Read it. Follow it.

I think the break-in period is so the gears set in the rear diff...or something like that. It doesn’t have anything to do with the engine. As for the first oil change, there is no wrong answer. Go a full cycle or change it early...it’s your choice. We’ve had a few high-mileage engines on this forum that the owners reported just following Ford’s recommended maintenance plan.

I have never driven one of my new vehicles easy and never had an engine issue. First oil change at 3000 miles then 3500 after that except this one I am doing them at 4000.
All 6 new vehicles went over 130k before selling them. One was just over 200k and one went to 299k. Parts and oils are so much better now you really have to neglect a vehicle for it to not reach 150k. Hell, my brother treats his 2001 F250, V10 like crap when it comes to maintenance and it's over 250k.

Bottom line is break it in and don't be easy on it. The rings are moly with plasma cylinder liners. If you don't break it in with some heat and high cylinder pressure the rings will never seat.

Do the new 5L's still use 5W-20 or did Ford change that to 5W-30 in light of all the engine issues?

Ford is so European in it's thinking with regards to oil change intervals. Oil is very expensive over there and and they extend their dump cycles to 10K or even 15K miles. That's ludicrous and for those of us who remember using 10W-40 oil and changing every 3000 miles as per the owner's guide, the very thought of extending to that duration would almost make me grab my chest.

In my 2011, the OLM is factory set to 10K miles or when the oil is used up. The disclaimer in the back of the oil change guide states "if the OLM fails, change the oil every 5000 miles". So, I'm at 92,000 miles and I've changed the oil every 5000 miles since new. No issues what so ever.

As for vehicle break in, I've always been told to break it in like you intend to drive it.

The oil requirement for my 2016 5.0 is 5W-20 and unless something has changed, the same 5W-20 applies to the current generation 5.0 as well.

I also agree with you on the break in procedure and it’s what I’ve done with every new vehicle I’ve ever purchased and I’ve never had any problems with longevity.

If you baby a new engine, it's probably going to be an oil burner. That's especially true with the new 5L (with plasma coated cylinders). Don't run it wide open for 200 miles down Highway 10, but don't baby it, either. High cylinder pressure is what's needed for those rings to form to the walls before they are glazed.

Have you ever seen the first oil changed on a new engine, or had analysis done on it? There is a LOT of metal floating around. It should be changed earlier than normal, even if your cousin's brother-in-law's neighbor went 10,000 on his first interval, and the engine still ran for 200k.

Just so everyone is clear, plasma coating is the process of spraying the metal plasma on the cylinder walls, not the coating itself. Once the molten metal is hardened on the cylinder walls, it's no longer plasma, so they don't have "plasma liners". I believe Ford is using mostly iron, but it can be done with other metals.

You win the free hot dog!!!! It's all about the rear differential.

Posted elsewhere on this board:
I have a 3/18 build on my 5.0. The first oil change was early at 3,000 miles. After that, it burnt around 2 quarts in 6,000 mi. Yes, I didn't drive it hard. This was before the TSB came out but I heard to try to replace the PCV around this time. I confess I was a little worried. I decided to drive it hard in sport mode for a couple weeks before the second oil change to try to get it broke in. Now at the second oil change, 11400, it has slowed as near as I can tell.
Update:
I am at 16400 now and it has used 38oz of oil which is 1.18 quarts in 5000 miles. I can live with that and it does seem to be slowing.

I had a similar experience with my 5L (2016). It had about 300 miles when I picked it up (dealer exchange), and apparently it was babied. It was burning a lot of oil, but I took it on a trip through the mountains, and the big hills seemed to do the trick, because it stopped burning oil. 20k on it now, and doesn't use any oil between changes. That's the last time I buy a new vehicle with that many miles on it. I want to be the one breaking it in.