They might say break in oil because they have smeared every moving part with assembly lube. Was the oil grey? I've never heard of break in oil but it could also be called that just because it was the first oil in the new engine and not a special blend. Like someone above said, it could have metal in it because of the machining done to the engine. That or the assembly lube angle would be a good reason to change the oil. It is never a bad idea to change a new engines oil before the normal recommended interval. There is a slight chance that there was some metal shavings left in the block. Unlikely, but possible. Magnetic drain plugs are a good idea as well. If it is a high dollar engine, buy yourself a filter cutter and check for filings in the filter. This is way overboard in my opinion but not crazy. We used one on my buddy's drag car and it let us know if the motor needed a refresh. Most times it blew up before we even had to cut the filter. Lol. Lots of nitrous in a competitive class meant often having to put the BIG jets in for the finals. The burnt piston (s) was/were worth the prize money. The turbo he put on later was alot nicer to the engine. He ran synthetic in every version of that car and his next one too.
Synthetic vs standard oil...six of one, half dozen of the other. They have both been around for awhile. You're gonna get, and have gotten varying opinions. Just like with everything else you want to buy. Just read the reviews on anything you are looking to purchase. 5 star rating in between 1 star ratings. I gave up on trying to buy plastic 6 gallon tanks because I couldn't figure out from the reviews if they were the cats meow or complete junk. I just rebuilt my metal ones. I know they won't leak or distort. Lol
