The Loggers I know that use Stihl Ultra oil say their saws last about 1.5 - 2 years mixed at 40:1 - 50:1 with ethanol 87 octane. I wonder if they used a higher viscosity oil, like these racing 2T oils, mixed at 32:1 how much longer would they last?? Some Loggers have told me their saws don' t last 6-12 months on Stihl Ultra at 50:1. I've told this before but one Arkansas Logger said his 372's started lasting longer (almost twice as long) on Safe Guard 2T oil, cheap stuff, after changing from a 50:1 mix to a 32:1 - 38:1 mix. He also uses cheap gas (87 ethanol).