Robin Long <rlong@matrix-controls.com> wrote in message news:<BC9CE8DC.5E62%rlong@matrix-controls.com>...
> Nowadays, with better engines and better built cars, is it still necessary
> to break in the engine? If yes, how?
>
> I have heard of some who recommend running at full open throttle on some
> load to "blueprint" the engine. How does this actually help "blueprint" the
> engine?

Yes, but not as critical as it used to be due to better manufacturing.
The 2004 Accord manual states 600 miles as a break-in period. Avoid
hard acceleration, particularly in first gear. Don't tow anything.
Change the oil at 5,000 miles or so. Don't brake hard if you can
avoid it, for at least 200 miles. Vary your engine speed -- this and
not flooring it are the 2 most important items IMO. Ultimately if
you're only keeping the car for 50,000, you can abuse the hell out of
it; the next owner will suffer.