I have used Bakers AA grade of castor oil from SIG Manufacturing for years. It’s “fuel grade” oil. It ran clean and well. Because the cost jumped to $40 per gallon plus shipping, I looked at other cheaper alternatives to try out and see if I get the same performance and qualities at a cheaper price. I tried a small bottle of castor oil for apothecary purposes as a test. I used it in fuels for all three engine types I use - marine, aircraft, and surface. Of these, the aircraft engines often run the hottest. I noted good properties and burning characteristics. I did a lot of experimenting with different oil concentrations and blends in my truck engines. Attached are pictures of my Novarossi Legend 28-8RT after 2 gallons of my “apothecary” fuels. Cardiak has seen this engine/truck run, so I’d think he could vouch for me. Not all castor oils are created alike, true... But oils for soap making and cosmetics rarely have additives as they could cause undesired effects in people with allergies.

Things are different in other parts of the world though, and you must remember that. What’s available to you may or may not be the same thing available to others in other countries.

You guys have to understand - like you, I have a lot of years and experience in this hobby. I would never recommend something if I haven’t had good results from it. I treat my engines with the utmost respect, but I also put them through their paces. I’m no racer, but I don’t have to be to test the limits of anything. But take what I say with a grain of salt. What I do works for me, and because of that, I’ll stick with it.

YMMV!!