The difference is that synthetic is adequate as long as you don't go lean, on lean runs castor provides better protection. You may very well run all of your engines rich enough that they never encounter a lean run. As long as you do, you will most likely never have a problem. Many people don't have experience in proper tuning techniqes and as a result, run engines lean and damage them. Castor provides better protection in that case.

After all, what the heck would many of the engine manufacturers advise using a castor mix in their engines. You would think that after millions of engines they would have fiqured out by now that castor is totally useless. How many engines did you build before you fiqured it out?

If you don't like castor then don't use it but coming in here and acting like those that do use it is somehow less intelligent doesn't help your argument.