I believe the instructions say to use 50:1 petroleum based or 100:1 Amsoil. I had talked to Dave at DA and all of their engines are running 100:1 amsoil. I prefer to give it a little more oil than that until I have more time on it. The prop change was the following weekend. I changed to the 24/8 since I like the way it flew my plane better thant the 22/10. the 10 pitch just made the plane fly too fast for me. I had run a 22/8 for a while while running the 32:1 mix and it was ok, but the vertical performance suffered. Again Dave gave me the tip to try the 24/8 and he is absolutly right. This pulls my 21lb. Edge vertical without any problems. You can even hear the tips poping. What a difference this all made.