l was out many pages ago due to one or two that have never had a foot up the a$$. But l keep dropping in to how many times ya's all been round the track. Its an endless journey the oil thread it just goes round and round but l must say its kinda dappa when the op posts Belray's side of the story and stuff. My saws parts and plastics wear out way faster than the engines. l have seen many stihl saws run on stihls cheapest orange bottle stuff and seen decades of service on farms. l can replace many of my saws within two years buy NOT running top dollar name brand ester base full synthetic oil. l think your better off finding a 'good' oil at a 'great' price, its actually easy. Full synthetic's biggest negative is price and you have to consider that in a commercial situation. There are plenty of fd rated semi synthetics out there at a fraction of the cost. You also need not worry about slow/poor ring seal during break in, rust, glazed piston's, loss of throttle response/power if one chooses a sensible 'semi synthetic' oil. Many semi synthetics are rated higher than their full synthetic cousins and give you kinda the best of 'both worlds'.