Well, I cannot certify if 100:1 is OK or not. There is an earlier poster on this thread who claims he has been using it at 100:1 on dozens of 2-cycle equipment including chain saws, weed whackers, hedge trimmers, etc., for many years without problems. I am reluctant to go that far. But the main things that would allow such a ratio are stability and low volatility under high temperatures. If there is enough oil present to coat all wearing parts, any more oil than that just goes out the exhaust anyway. Remember, 16:1 was once the norm. Now we have most people accepting 50:1. For me, I will use 50:1 as an insurance policy. If I am wasting some oil, so be it. Maybe after a few more years, I will try 80:1 if more and more people get good results. But the cost of the oil does not mean a lot to me when compared to the cost of the equipment I am using it in.