[Fast Eddie]

The main advantage of synthetic is that it is not prone to it vescocity (which is usually better to begin with), ability to flow, breaking down nearly as easlily as conventional oil. Guys in NASCAR qualify w/ 0 weight and some race with it, I'd think if you can have the OIL temp guage pegged in a NASCAR for 300+ miles and the oil does not turn to sludge there is something to be said for it.

That being said, it means you do not need to change your oil as often b/c the oil is not breaking down, however the oil still gets dirty, How dirty is more a function of the oil filter, obviously, and how the engine is running, but I bet the syn probably comes with better detergents; so it still needs to be changed.

As for the MYTH about changing from dyno juice to syn and back, its just that, a myth. the only time this really comes into play is while the engine is still breaking in, usually the first 3-5K miles or so when the seals and everything are seating. then you want conventional.

As for sucking out all the old oil and what not, its cool to just drain the oil conventional oil and dump in the syn. even if there is some old stuff in there your cool, what do you think the blend stuff is, part syn, part dyno.

Disadvantage is syn costs more.