filter it and pour it in your tank. It'll be fine

__________________
2004 F150 4.6L -My Daily
2007 Volvo XC70 -Wife's Daily
1998 Ford F150 -Rear ended
1989 J-spec 420SEL -passed onto its new keeper
1982 BMW 733i -fixed and traded for the 420SEL
2003 Volvo V70 5 Speed -scrapped
1997 E290 Turbo Diesel Wagon -traded for above
1992 BMW 525i -traded in
1990 Silver 300TE -hated the M103
1985 Grey 380SE Diesel Conversion, 2.47 rear end, ABS -Sold, really should have kept this one
1979 Silver 300D "The Silver Slug" -Sold

Ugh, this kind of thing just won't go away.

Lubricating oil used in a engine isn't designed to be burnt and we have changed the oil because it is contaminated, why would you want to run it through a injector pump with clearances much smaller than a crankshaft
? Same goes for ATF or rear end lube.

Lube oil has additives that leave ash , carbon and other bad stuff when burnt. Find someone that has a waste oil heater and ask then what kind of junk is left in the combusion chamber and how often they need to clean it out. Do the same for a heater that uses fuel oil. ( Fuel oil / heating oil is diesel fuel dyed red )

Sure you can get away with burning old oil but at what potential cost? If you got the used motor oil clean enough, would you dump it back into your crankcase?

Maybe 4 - 5 times in the past six years, I've added a gallon of used oil to a tankfull of diesel on my W123s. Either the relatively clear motor oil or ATF from one of my gassers that sees lots of highway miles. Never the sooty diesel-oil though.
Did have a problem one time, plugging the primary filter on my first 240D. Changed that filter and it was fine.
In warm weather, I used to have signficant pinging (nailing?) with my latest 240D under part-throttle. That noise went away after adding a gallon of ATF from my '96 Camry.

Happy Motoring, Mark

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DrDKW

Think for a minute what the pistons and valves look like on an engine that is burning lots of crankcase oil, all gummy and nasty and carboned up, right?

So why simulate that on your nice tight engine by adding oil to the fuel? A gallon of oil in a tank of fuel would be like an engine burning a quart of oil every 100 miles of driving. Youre taking a good engine, and making it duplicate a worn out one....

ATF is definitely different from motor oil.

__________________
Strelnik
Invest in America: Buy a Congressman!

1950 170SD
1951 Citroen 11BN
1953 Citroen 11BNF limo
1953 220a project
1959 180D
1960 190D
1960 Borgward Isabella TS 2dr
1983 240D daily driver
1983 380SL
1990 350SDL daily driver alt
3 x Citroen DS21M, down from 5
3 x Citroen 2CV, down from 6