HuskStihl
Chairin'em for the sound
Young Bob (and come to think of it, Old Bob as well) runs ported saws. Specifically for Bitz a 390xp. I just looked at the husqvarna 390 owners manual for Sweden (in Swedish). For the 390xp they recommend a 50:1 ratio of husqvarna oil, but a 33:1 ratio of what I think is any other approved oil. Legally, I don't think you can recommend 33:1 in America. So the manufacture is comfortable with a 50:1 with synthetic oil without EPA interference, but recommends 33:1 for what I am assuming is non-full synthetic. This is also for saws with 155ish PSI stock. I would be comfortable running full synthetic at 50:1 in a stock saw if Husqvarna is. At 210psi, I'm liking more oil. If I'm buying less expensive oil, I'd be mixing at 32:1 as recommended by the manufacturer in the absence of the EPA. Clear as mud