jeffcoslacker wrote:

> Knifeblade_03 Wrote:
>
>>A lot of yes/no regarding use of synthetic oil, so it a hard call. But,
>>I would foolow your friend's thinking by changing oil and filter at 1K,
>>2.5K, and again at 5K. It not expensive [meaning the oil changes], and
>>they get rid of any flotsam and jetsam created by a new engine break-in
>>period.
>
>
> Used to be there was a lot. Now there's none...

I haven't observed any difference in the past 40 years or so. Rings
seating will ALWAYS generate about the same amount of fluff, and if you
do NOT get that fluff, then the rings aren't seating as they need to and
the engine will be a chronic oil-burner. There should be minimal-to-no
material shed from bearings during breakin, none from a roller cam, and
only a slight amount from a slider cam. Its really the ring fluff that I
like to get out of the system. Yes, the filter catches it, but a
filter failure (they do happen!) can dump it all right back in. Better
safe than sorry.

nothing an oil filter
> can't deal with anyway. Back in the day, real fine finishing machining
> wasn't fast enough for production vehicles, and the final finish was
> achieved through friction, the main area being cylinder wall to ring
> seating...and other direct contact areas like pushrod to rocker contact
> and lifter/cam...

I think you grossly under-estimate the precision of older engines. A
rougher cylinder wall finish was specified with bare iron rings, yes,
but it was NOT expected to "finish itself" on breakin. That rougher
finish was just required for oil retention with bare iron rings, and
stayed there through the life of the engine. Chrome finished rings
require a much smoother surface, but the total amount of material shed
during breakin is basically the same.

>
> But the surface prep on parts now is so good, usually the parts'
> surface is even better when new and unrun than it would be after a
> run-in period...therefore, no debris generated...techniques for
> controlling cleanliness of the assembly areas are also much improved...
>
> Had a friend buy a Civic Si a couple of years ago, and he was wondering
> the same thing, and was told by the service dept to run it normal for
> 500 miles and then drive it like you stole it..and go with the printed
> reccommendations for oil change intervals...
>
> 74,000 miles of his daily abuse, and it still uses less than 1/2 quart
> between changes, same as when it was new.

Half a quart between changes is pretty excessive, especially for a
4-cylinder. My last "brand new" engine (1993 Chrysler 3.5L v6) burned
less than a few ounces (not measurable on the dipstick) between changes
from about 10,000 miles to 180,000 miles or so. Now at a little over
240,000 miles, its crept up to about a quart to a quart and a half every
7000 miles (the change interval with Mobil-1). Some of that is leakage
from valve cover and pan gaskets, though.