i have in the past metered it in with full tanks of fresh gas.  the
process i used was this

1. drain fuel in to clean container and let it settle out large particles
for about a week.

2. filter the fuel with a fine mesh filter (binks paint filter), pour
slowly and as you get to the bottom stop so that the sludge and large
particles don't get into the filter.

3. leave the filtered gas to sit for a week.  if there are no particles
in the bottom of the container after a week, begin metering it in when you
fill up the tank.  i was putting a half gallon per tank full, and didn't
suffer any negative side effects other than a small smell of stale gas
once in a while.  i also ran a bottle of fuel injector cleaner after the
process was done.

jonathan

On Fri, 25 Jul 2003, Bradley Flubacher wrote:

> I have about 5 gallons of old diesel I must dispose of. I've been trying
> to for several months now, with no luck! Let me know what you find!