WMO= Waste Motor Oil
WATF= Waste Automatic Transmission Fluid
As for when you burn it, exhaust comes out the tailpipe
(sorry, I couldn't help myself). Seriously, nothing out of the ordinary. If you get your WMO blend really high, you might see a little more smoke. ATF is one of the best injector cleaners for a diesel engine you can use. My IDI runs great on both.
