I've used my 046, MS 461, 051, 056, 066, MS 660, 076, 084 and 090's on my mill.
Some crazy person offered me stupid money for one of my 090's so I sold it.
My 084 was actually used in the filming of The Miracle Mile so it is now a shelf sitter.
The other saws get used, depending on the size of the logs and which mill I use.
As far as the oiler, there could be many things. Milling is hard. The top plate angle is key. If I put a standard chain on my mill with a 30 degree top plate angle, it will smoke like crazy.
Same chain, same oil but the top plate angle at 12 degrees, the chain cuts right through and no smoke.
The simple explanation is the chain cuts easier and generates less heat.
When ripping, I will use two tanks of fuel to every tank of oil.