OK, OK we all know why synthetic oil is better be it’s superior heat transfer, slower deterioration or all round better performance. I would like to discuss one situation in which raw oil is a better solution to synthetic. Now keep in mind this is a pretty specific case and is not recommended, but none the less it is an option. In order to understand this you must know the difference between the oils molecular structure. You see synthetic oil is perfect in almost every way including the size of molecules (think the size of each particle). Raw oil however is a little less than perfect leaving molecules of varying sizes which admittedly helps cause “sludge” build up in the engine. This can be used as an advantage of sorts. Have you ever owned an old quad or trike that always had an oil residue on the head that looks like the valve coves are leaking but you never see it leaking unless you pressure wash the shit out of it? Maybe you have had an old vehicle that when you look under the engine you see an oil/road grime on it but never see a puddle under it? Perhaps you switched your vehicle over to synthetic and now it leaks? This is due to either A: the bigger molecules actually plug the leak or B: it mixes with dirt easier making a “paste” of sorts plugging up the leak. Think of it like this the leak is a door and when a few of the bigger molecules of the raw oil try to go through they get stuck plugging the hole closing it off bit by bit. Synthetic on the other hand are all the same so if one fits they all do and they don’t really like sticking to each other. So if you have an older machine and it seems to be doing just fine with raw oil perhaps don’t fix what ain’t broke.