IMO, there's 2 kinds of smoke oil : Super Dri, and the ones that don't work very well.<div>
</div><div>ATF fluid has a couple of drawbacks, imo.  First, its smoke is not as "dense white" to me.  Second, it attacks covering far more than ASO does.</div><div>
</div><div>Concrete mold release, as mentioned above, is not the greatest environmentally, and from what I've seen, is now even MORE expensive ($45 a gallon on ebay, but I didn't search very hard) than ASO.  Of course, bowers says he's using it in 1:1 applications, so maybe there's a cheaper source in large quantities or something.</div><div>
</div><div>Diesel will certainly work...but again, the smoke isn't as thick, and it takes a LOT of it to get large plumes...more than you care to carry around in an airplane, I'd wager.</div><div>
</div><div>Finally, for me at least, ASO is a known entity.  In the video below, there's no "heating coils", no fancy "smoke muffler", not even a fancy "smoke pump" that's somehow slaved to the throttle.  None of that.  It's a $9 windshield washer pump dumping ASO into stock DLE mufflers.  Period.</div><div>
</div><div>All ASO does is produce thick, dense, white smoke...every time...without messing with things.</div><div>
</div><div>[youtube]http://www.youtube.com/watch?v=si2vG3urjIw[/youtube]</div>