On Thu, 29 Mar 2007 08:32:22 -0500, "Courtney Thomas"
wrote:

Was the [assumed reliable] information you gathered with respect to big
over-the-road diesels, that...it's OK to burn the spent oil ?

If yes, in what proportions gas:spent-oil ?

I'm told that big fleet users do this all the time. The correct
proportion is 20 gallons or more of diesel to 1 gallon of waste oil.
Ideally the waste oil should be filtered before mixing but if you have
a big set of Racors installed that is probably sufficient.

Friends of ours have a long range cruiser which has an oil recyling
system built in.

Another possibility is using it for home heating oil. My old auto
mechanic back in the northeast does that, just pours it into the tank.