"dean" wrote in message
oups.com...
Because every professional user I have ever seen is using 10W30 engine
oil. Now I'm not about to put that into my Stihls but I was just
wondering if I am wasting money on expensive bar oil?

Any comments?

I've seen all sort of crappy oil used, even used motor oil. It works. OTOH,
I'm still on my first gallon of bar oil that I paid about $5.