i've read a couple of threads on running used oil, curious as to mixture, filtering, smoke level, power gain/loss, etc. any info i could get would be great.

be sure to let it settle for a couple weeks. then filter the oil on top of the crud, down to 5 microns, prior to use.
i'm using a rv water pump and a house filter.
this time of year, if your up north you may need to start using a heated system in the mornings or a blend with #2.
i've been running 100% wvo all summer in a idi engine. next fill up will be 70-75 % wvo as the nites are getting cooler here in the west.
remember wvo is not bio-diesel and using it is at your own risk.