Well I'm not going to write a book here. But I have been selling, testing, and using lubes for 25 years. It is my business. I'm not a "Lawyer", "Banker", "Butcher", or "Candlestick Maker" selling lubes. So I have seen it all. I have heard every sales pitch and gimic.
1. There is NO Motorcycle oil.
Oh there are bottles of oil that say there is. But like other things in our life. It is a sales gimic to suck you in.
2. The "Enviromental" additive is a myth.
3. Clutch slippage has only happened once to a fellow who insisted on running 50 wt and proved too thick to squeeze out and caused slippage because sythetic is slippery-errrrr!!!
4. The top 4 oils are (Not necessarily in this order) Royal Purple, Motul, LE, Texas Refinery
5. There are other good oils too for the street and ametuer applications.
6. Oils to avoid are your over the counter "S" grades whether they are Mobil, Shell, K-Mart, or any other of the 90% of crap out there. This stuff will keep your ride going. But there will be wear and if ANYTHING happens out of the ordinary. You will have damage. Like overheating (loss of coolant or an air cooled that is left idling in the hot environment).
7. Oil testing is as tricky as learning religion. Each company can bend it to suit what they want you to see.
8. So for the average guy or girl out there. No magic wand to teach you in a minute what to use.
9. Then you have old wise tales that are passed on through generations.
Ok, bring on your critosism.