^^^Consider that if we stacked 3 of our trees one on top of the other, they still might not be as tall as what you have out there. 

 That has a pretty serious impact on felling methods. 
I measure trees for a living so have a pretty good idea how tall they are on the east coast. While there may be a few which hit the 100 foot mark they are few and far between. 
On the subject of used engine oil; I ran it very briefly and decided that I didn't like the mess. At the end of the day the saw was just plain nasty, which increases cleanup time. I do have some partial jugs of unused oil which I sometimes blend with the B&C, the used oil I prefer to give to the local saw shop to burn in his waste oil furnace.