Changing oil often is the cheapest and #1 way to extend the life of an
engine.  If you wait till the oil is dirty before changing then you
waited too long.  Synthetics do not break down as easy as conventional
but they still get dirty just the same.  I change my oil every 3,000
miles.  It's just cheap insurance to avoid problems.  I see little to
gain be going longer except a few $'s for oil.  Not worth it.

Personally, I agree with a breakin period, but I wouldnt wait until
8-10K for the first change (didn't on a recent new vehicle of my own).
I'd change at perhaps 3-5K the first time, then switch to synthetic
0-30 (I'm not sure if anyone other than Amsoil makes that - that's
just what I use), and a GOOD oil filter (a "depth" type filter, not
just a paper pleated one such as Fram, etc.).  That combination is
what has allowed Amsoil to warrant their full synthetics for 25,000 or
one year (whichever comes first, of course), assuming a mid-cycle
filter change.  I haven't changed my oil in under a year for at least
25 years now, and have driven every vehicle well over 100,000 miles
before selling or trading (still in excellent engine condition, with
good compression).

You might also want to consider a better air filter than just a
standard pleated paper filter, also.  I don't have any experience in
over 25 years with anything other than Amsoil (I'm a non-active dealer
- just get it for myself), but they make a foam filter that you
periodically wash and re-oil that will run circles around a paper
element filter in terms of amount of dirt it traps, and the much
smaller sized particles it traps.  That's where much of your abrasive
contamination comes from in an engine - the air intake - so it makes
sense to clean that up also (and regularly).

The extra price of the oil/filter/ and air filter are easily made up
when compared to a 3K change schedule (even longer, for that matter).
Once a year for the oil, twice a year for the filter, and perhaps only
one air filter for the life of the vehicle that you simply clean and
re-oil periodically).  Yes, I pay a little less as a dealer, but if
they took away my dealership status, I'd still go with exactly what
I've been using for over a quarter century.

C.R.