MCW
Somebody's talking crap here & it ain't the tree!
Was running a brand new 661 a week ago with a 36" .404" .063" Stihl ES bar with Windsor semi chisel non skip on a 7 tooth rim. Did it easily buried in dead Sugar Gum which is HARD stuff and harder than basically anything you'd find in the states. Was a very impressive saw. With the oiler pin adjusted there was ample oil. Saw was an Australian delivered model bought by Ben (Bennn*e).
.063" bars will definitely carry more oil as .050" bars tend to pack out the groove with woodchips a lot easier. Not all timber species tend to pack out the bar groove but it's not uncommon in our timber to have woodchips jammed that tight in a .050" groove that it is a real struggle to get them out even with a bar cleaning tool. You don't see this in .063" bars.
If Stihl started saying that you could run a 42" bar on a 661 they'd never sell another 880
.063" bars will definitely carry more oil as .050" bars tend to pack out the groove with woodchips a lot easier. Not all timber species tend to pack out the bar groove but it's not uncommon in our timber to have woodchips jammed that tight in a .050" groove that it is a real struggle to get them out even with a bar cleaning tool. You don't see this in .063" bars.
If Stihl started saying that you could run a 42" bar on a 661 they'd never sell another 880