After searching high and low for a good 2 stroke synthetic oil I came across 2-cycle TCW III Racing from Royal Purple. (www.royalpurple.com). All I can say is whoa, initial tests shows vast improvement on engine running, including quieter running, easier starting and better rpm. My initial run was 50:1 mix and it was on a stubborn engine for running and getting the mixture right, one tank with this new oil changed my concept of this engine. I thought initially this was a fluke, however running this mixture on 4 different petrol engines of all sizes from 4 different manufacturers, rpoved to me that this oil needs to be promoted in the model world.