I concur... JAG's comment was unfair and, unlike most of Haas' work, completely worthy of being forgotten.
I like the idea of breaking in an engine with a light oil and light exercise followed by a 500 mile oil drain. From there, go to the oil you will use and up the work level to moderate for another thousand miles followed by drive "normal" (whatever that is to you) and a 3-4K interval. Follow that by the normal interval. It's just "what I do" and not based on a lot of study. May not be right or efficient but it can't do any harm either.
Some people say an engine breaks in better on a mineral oil, citing the higher friction aids break in. I guess that implies the mineral oil is like using a "medium grit polish" to start a valve lapping job followed by finer paste and a smoother finish. I've always followed that oil axion but have never seen any scientific "proof" that it's best (but would like to see proof of something one way or another). Sounds logical but I have seen (not close up) engines broken in on synthetic and they seem to be fine.
I do know that the relationship between ring material and the type of hone used on the bores plays a part in ring seating. In those cases where a mismatch has occurred in this area, the oil plays a big part and that's were a less slippery oil helps. Anyone else used BonAmi or Comet to seat rings that just wouldn't?
I'm not following my own advice on my latest overhaul on a diesel truck. Because it has a bypass oil filtration system, I'm going to run a normal interval from day one.
These days, I'm beginning to think the "run normally from day 1" crowd is right, at least as it applies to a newly manufactured engine. I have been to a number of engine plants and watched engines being built and tested. The DMax plant in Moriane, Ohio, stands out. At the time I did my tour three years ago, literally every engine was hot tested. They said they'd been doing that since day one and I presume they still are. It's all pretty much automated. A robot cart carries the completed engines to one of a long line of dyno cells. Robots attach the engine to a dyno, a human makes a few of the hookups, it's started, warmed up for a couple of minutes, run lightly for a few and then tested at full rated power. Total time under 15 minutes. If the engine passes all it's tests, it goes into a crate. If not, it goes to a diagnostic area for repair. The above is similar to other plants, though not all of them hot test every engine.
You gotta figure that if it's OK to run a brand new engine at full power when the paint on the block is barely dry....
But I don't thing this would apply to a rebuild or a home job, because the standards of cleanliness are usually not as high as I've seen in a modern engine factory. The standards of machining may not be as good either (I've see my share of what you might call "loose tolerance" machine work). It's the built in dirt and break in materials you need to get out ASAP because it can be a killer. I know guys that will run an engine 30 minutes and change the oil and filter. It's hard to argue against that given some of the junk you see in the drain pan.