I have run them with 10, 15, 20, and 23% oil. I am very happy sticking with the 20% oil as the engine runs cooler and seems to be much happier long term. After talking to Richard at YS, the lower oil engines definitely wear faster (which is to be expected). The smoke trail with the Low Smoke series fuels are minimal anyway, so I don't see a major advantage to the 10% oil.

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