Originally Posted by
airraptor
Remember most manuals are written by the MFG and could protect them more than help the user.
Most tell you to use castor so that the engine is protected more when ran hot and lean. They have to write that manual to host a range of people from beginners to experts. They lean more on the beginner than the expert. If they told what to run for best power and expect you to tune correctly then they would. Now if the new guy ran the engine lean burned it up and wanted a warranty exchange they would go broke.
I find it funny how people talk about thinner and thicker oil saying this or that but its mixed in with methanol and the viscosity is much closer to that of the methanol lol.
The viscosity is far thicker than that of methanol. It may seem about the same but if you measure it is not. Methanol has a very low viscosity and no lubricity. When between two metals the smaller methanol molecule is displaced by the thicker oil molecule and the castor molecule is much longer and thicker than the synthetic. Which is why it protects better but also not as slippery.