I'm going to have to disagree with the first statement regarding change intervals. See my response in the following thread:
https://www.s2ki.com/forums/showthread.php?...ighlight=sludge
You should always change at intervals no greater than recommended in the service manual, not only for waranty reasons but for reasons I indicated in the other thread.
I believe the reason synthetic oil costs more is because it undergoes a much more extensive refining process and it gives a "perceived" advantage in lubrication. I say perceived because although I believe that synthetics lubricate better, flow better and have a wider useable climate range, some people still debate this issue. 3000 mile oil changes are the norm in my book and I still will use synthetic because having done so the last 15 years, I've had no engine wear issues in any car I've owned. Before synthetic use, I did. Call it superstition if you like, but I'll stick with synthetic @3K mile intervals.

 

Take a look at a few of these articles if you don't believe me. There is also a ten-page thread on http://www.honda-tech.com/ about oils which is extremely in-depth:

http://www.rconcepts.com/beard/dragnet/dra...ag/oilinfo.html

http://www.honda-tech.com/zerothread?id=163845

Synthetic oils are made to be ran for longer intervals w/o their viscosity breaking down. Granted, synthetic oils are typically better for higher revving engines than conventional oils, but most of the synthetic oils that are commercially available show no difference than the less expensive conventional oils.

 

I scanned the "honda-tech" thread for the first few pages. These are posts from individuals offering their personal opinions. As with any forum, including this one, personal opinions are just that and have no basis in scientific fact. Take it or leave it.
I also read the Ed Hackett write-up. Again, I don't know who Ed Hackett is nor has he supplied any data that can be verified (I'm not saying that I agree or disagree with all that he writes). They're just a bunch of numbers on a computer screen. But for the moment, let's take what he wrote as gospel. He has stated that the more expensive synthetics are indeed a better oil for the reasons that he gave. I personally, already believed this. Funny that you don't and yet you quote his write-up. He also states that car manufacturers AND synthetic oil manufacturers state that change intervals dictated by the service manual be adhered to for warranty issues. (I wonder why?) Then his write-up goes on to say that "ash" content is what produces "sludge". The ash content for Syntec 5W50 was pretty much on the "high" end of all the other oils. So this would indicate that it would sludge up no different than any of the other oils over time. Ironically, the "ash" numbers for the other expensive synthetics were missing. Still he says that they can be left in the car 2-3 times longer than the other oils. Having been a scientist for over 20 years previously, this statement is made without data to back it up. I'm sure if pressed, he could come up with some as I'm sure you could link me another site that could give me that data. However, that data should contain sufficient "N" values, "t" tests and other necessary imperical data to justify the "conclusions" stated and also with the appropriate "references" at the end to back up statements made where numbers are taken for granted. Without these, they simply become "opinions" and numbers presented on the internet as is so much other stuff.
Please don't take this as me NOT believing you. I mean no offense. It's more to do with what you have come to believe. My beliefs are based on my own experience, my own experiments and my own findings based on my circumstances and my reality. And you (or anyone) can take it with a huge grain of salt since, these too, are just a bunch of words on the internet.
I know that synthetics (especially Mobil 1) is a superior motor oil based on it's performance in my cars.
I know and have confirmed the better cold weather pour characteristics of Mobil 1 synthetic as compared to a name brand non-synthetic from my own freezing/pouring experiments.
I know, for a fact, that I cannot leave a synthetic oil in my engine for 2-3 times longer than a conventional oil due to the sludge buildup (and this was with changing the filter at the usual intervals too).
If this is superstition, then so be it.
I stand by my last post. (with respect)

 

http://www.vtr.org/maintain/oil-overview.html

I usually post this when the oil issue gets brought up.

I have personally tried the AMSOIL and really like the quality although a bit on the expensive side. I do however believe in using dino for at least the first 7,500 miles on any new car but that is just personal preference. Castrol conventional is what I have used in my previous 4 Honda cars and is what I use now in my current Accord. Like it says Drive Hard.

 

Not to rant, but this topic has been discussed ad naseum on every automobile enthusiast site known to mankind. Debating motor oil preferences (and interval changes) within the confines of this forum usually encourages links to a hundred OTHER opinions from OTHER forums.
Here's my .02
There are always two camps:
Regular dyno oil and synthetic. With the former, the discussion doesn't end there...it can continually be debated regarding WHICH synthetic is best: Redline, Mobil One, Amsoil, Royal Purple (my choice), etc.
I think there is no correct answer since for every happy synthetic owner, you'll find one who is loyal to Castrol GTX 10W-30. As for me, I'm sticking with the showroom oil until 5K and then I'm moving to 5W-30 Royal Purple (5W is a bit more fall/winter friendly here in New England). I'm not waiting until 7500 simply because so much of my driving involves short trips and stop and go traffic. I think the correct answer to these questions regarding which oil to use and such depends greatly on the INDIVIDUAL'S driving style. Someone who spends their weekends with the S2K and their weekdays with something else probably doesn't have the same requirements as others who punish their cars (in a good way of course!).
Just my own .02
Once again.

 

[QUOTE]Originally posted by xviper
[B]
I believe the reason synthetic oil costs more is because it undergoes a much more extensive refining process and it gives a "perceived" advantage in lubrication.

 

 

hmm...after switching back to regular Honda oil, my MPG went up by 2.7MPG per fill (no changes in driving conditions) - i guess everyone's experience is different. and the reason why you don't want to change oil too early on the new car is the alleged (i remember people debating about that to no end) molybdenum particles (acting as break-in agents) in the original factory fill. my honda service adviser (one that i actually trust and respect) also stated that regular oil is fine (it would've been easy for him to sell me the mobil 1 synthetics on his shelf and easily charge me for an extra $20) and i'd probably want to stick with that for the F20C.

i think the bottom line is: whatever tickles your fancy

 

[QUOTE]Originally posted by mingster
[B]

hmm...after switching back to regular Honda oil, my MPG went up by 2.7MPG per fill (no changes in driving conditions) - i guess everyone's experience is different.