@tardrex But you guys probably drove only short distances. In my OP, I’m talking 80 miles. But OK, I get the message from everyone here: how a car is “broken in” is only a small part of the overall picture.
I want to thank everyone who responded with their insight, knowledge and experience. You folks really know about cars!
Yep, there’s a lot to be said about loading the rings early in the life of a rebuild/new engine.
I believe most engines are now broken-in at the factory, making this a moot issue. In addition, those cars that do come with instructions for some kind of break-in don’t usually come with the same type of break-in instructions cars used to have. For example, when my parents bought a new 1989 Nissan Maxima back in the day, it came with instructions not to drive it hard for the first 1,000 miles and not to drive it at the same speed for extended periods, but the Ford Escape my sister bought a few years ago came with absolutely no break-in instructions at all, and the vehicles I’ve seen that currently come with break-in instructions only warn you not to drive at the same speed for extended periods. In fact, my sister’s Ford Escape was kind of a unique experience, because nobody at the dealership seemed to know if it needed an oil change after the first 500 or 1,000 miles, because nobody at the dealership knew if it used special break-in oil.
Manufacturing techniques and build quality have improved over the years, so although I do worry how a vehicle was treated before I bought it, I worry more about how it was maintained than I do how it was broken-in/driven. The owner’s manual with my mother’s 2002 Toyota Sienna said that it was normal for the high compression engine to burn oil, so an engine can burn oil for reasons other than improper break-in procedures.
The one area I do worry about how a vehicle was broken-in is with motorcycles. Cars come shipped from the factory ready to drive (sometimes with the engine already broken-in at the factory), but new motorcycles don’t get fully assembled (with a battery and fluids) until they’re purchased, so they do have break-in instructions and you do have to do an oil change after 500 or 1,000 miles on most models.
Wow. That’s pretty much what I said, but you said it in one sentence. Impressive!
My understanding is that the 600 - 1,000 mile break-in period is more for the drive train. Steady speeds can set up harmonics in the gears such that they produce an “unhealthy” early wear pattern. Another way to say it is that the drive train parts need to “get to know each other” at low power and varying speeds.