Auto Racing: Synthetic oil, supertech oil filter, water condensation

Question
Hi, your expertise area sounds as though you might be able to help with a disagreement that always comes up in our online motorcycle club.
The guy that sells me synthetic oil (Amsoil) says I don't really need to change the oil because there is nothing to "break down" as there is in natural oil. He said change the filter only. I have no opinion, but here is a common answer in the club:
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What happens with the oil is contamination from water condensation, carbon
deposits, and dust accumulation...all this together causes your oil to
become contaminated and slightly gummy regardless of how much money you
spend to get a good quality of oil for your vehicle.
If there was a precision built engine with no leaks what so ever, then
BINGO...I could understand going every other time with the oil changes.
Another thing to consider is the filtration. They are okay but only collect
certain particles.
Oil does not wear out it gets contaminated. Used oils can be recycled and
reused again like new. The molecules remain intact.
At one time I used to use Castro Syntethic 5-50 for all of my bikes.
I quit spending big bucks on oils and now use the Walmart Superteck 10-40
oil (5 quarts for under $7.00 and also use the Walmart Supertech Oil Filter
ST6607 and fits perfectly for the Pacific Coast.
Change the oil and not more than 4000 miles...I try to do it at 3000 right
on the nose.
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Any expert opinion or can you guide me to someone who could give one?
Thanks for your time I appreciate it.
Aloha,
Jim Day
Honolulu, HI

Answer
Jim-

  Well...the truth lies somewhere in the middle.  Amsoil is certainly top quality and you probably could go for a good long time without changing the oil.  The problem is that unless your engine is in a perfect state of tune you'll get things like carbon deposits and such (as mentioned in the comment you left) and oil filters simply don't grab everything.  If you went with one of those super top quality oil filters that filter down to something like 8 microns (remember, a human hair has a width of 60 microns if memory serves), then I could see skipping several oil changes and just doing the filter.  However whoever posted that message couldn't pay me enough to use WalMart oil (unless they paid me enough for a new engine) so really it all comes down to quality.  If you're using Amsoil, I could see going 6 months to a year without a full oil change depending on how much you ride, but I'd still change it every so often just to be safe.  I personally use Mobil 1 both my Mustang and my truck.  I love Amsoil but since it's only sold through certain reps, it's not that easy to come by.  Royal Purple is great too, but generally a bit more expensive than I'd like to pay.  Even with Mobil 1 I try to change it every 4000-5000 miles.  Hope this helps.

Steve