I used to use Omega. My engines would turn brown from the burned oil on them. I'm sure they would then run hotter and hotter. Every now and then I had to boil them in anti-freeze to remove the burned oil. Then I discovered Cool Power only used synthetic oil. That oil burns at a higher temperature. I have been using Cool Power for about 4 years and my engines now always look brand new, run great, and seem to last forever. Like most clubs, our club has those that insist on using Castor Oil. I mentally chuckle but never say a word against it.