I've done that with my old 123. It burned nasty smelling. But it burned. Took forever before my clear inline filter "cleared" up too.

Make sure you filter very well first. and mix very well too.

Anything you don't filter your car's filter will have to filter out and shorten it's lifespan.

Don't worry about metal shavings and what ever in the oil husting your enigne. The car's fuel filter will catch whatever you missed. It just might clog faster though.

__________________
1987 300TDT
1981 VW MKI Caddy 1.6 diesel, waiting on engine swap
1983 D-50 Power Ram 4x4 "Mitsubishi" 2.3 turbo diesel
assorted gas powered crap and motorcycles

RIP: 1984 300TDT, 1982 300TDT, 1984 190D 2.2, 1992 300D 2.5, 1987 300TDT, 1982 Maxima LD28, 1983 Maxima LD28, Isuzu C223 P'ups X3, 1983 Holiday Rambler 6.2 Banks turbo diesel, 1984 Winnebago LeSharo 2.1 TD, 1985 Allegro 6.5

Dr. Pepper method is real close to the same as the Journey. The added Sulfuric acid makes things better.

This is the type of ignorance from lack of education that keeps me with plenty of used oil to run in my diesel (for the past 10yrs). If you want the truth about burning used oils in a diesel shoot me a email (As many people do). Yes you need to filter first(Of course gravel size chunks are bad-duh) but not with some military centrifuge (Simply settle,heat and filter through a basic coffee filter will suffice).The more you filter the less your stock filter has to work but anything (even metal particles) below 5-10 microns (which is what your stock fuel filter is) will pass through a IP and injectors with NO damage (This is what a fuel FILTER is designed to do, filter any particles LARGE ENOUGH to cause damage) I could go on all day about this but I'm tired of having a battle of wits with unarmed opponents!
Don't take my word for it, do some studyng (Oil analysis, etc..) then make up your own mind.

The only one showing ignorance is you. Fuel does not contain fine metal particles, used oil does.

People, you talk about used motor oil having metal particles in it. I agree, but I really dont think it matters. Your engine is the same type of enviroment as the fuel injections. you noth have moving parts rubbing on each other. Last time I checked my metal particles in my motor oil werent causing my engine to fail...


Just a though. But no really, theres no reason too. Dont do it. Waste of energy thinking about the harm it can do.

__________________
1981 300SD 512k OM603

The clearances in the engine are far larger than in the injection system.

Until someone can tell me difinitively its safe I am leery of trying. Its that. The oil and the fuel do NOT MIX in the engine for the most part except maybe a tiny bit in the cylinders themselves.

OIL does not go through your injectors. Fuel does. How small are the openings in the injectors? I have no idea. People are telling me I need to filter to 1 micron. thats really freaking small.

Now the injectors DO at least partially atomize the fuel right? how small is that. What is the larger "particle" they an pass without causing a problem? Clearly particulate concerns exist or we would not need fuel filters (multiple filters on diesels right?

I wish I had more info on this. I have access to SOO much used motor oil that I am drooling over the potential of using it in the engine without any of the hassles of WVO.

Experts here. Tell me what is the worst case scenario? Ruin the injector pump? is that it? is that the worst? HOW HARD is it to remove and install one of those ? I have an entire second car I MAY be up for taking a gamble in this regard as I could always gank the pump from the spare car and then stop using used oil if it causes problems.

Going 50% brings me from $4.79 a gallon to $2.40 a gallon :-) (I HATE that they are raping us on diesel now. Bastards :-(

Here you waltz in with one post, no credibility whatsoever trying to "educate" longtime forum members here who know better. Give me a break. When Stuttgart calls and says that filter used motor oil won't cause problems in their engines such as injector coking and other undesireable effects, let me know.

__________________
'81 MB 300SD, '82 MB 300D Turbo (sold/RIP), '04 Lincoln Town Car Ultimate

Sooner or later every car falls apart, ours does it later!
-German Narrator in a MB Promotion Film about the then brand new W123.

How many microns does the engine's oil filter, filter down to? Surely it couldn't be less than the fuel system's filters?

If you really wanted to, you could improve your engine's oil filtration system, by setting up a bypass filter...the kind of filters that use rolls of TP are the best...but others such as Trasko, will work just as well. That way, not only is your engine oil very clean at all times (longer engine life), but you can then use the used oil in your fuel, and not have to worry about these huge "metallic particles" that are floating around in engine oil.

__________________
Current cars:
2000 ML55 AMG, 174k miles
2003 C240 T-Modell, 202k miles
1995 S320, 207k Miles

Not really. The TP leaves too many gaps for oil to get around it, quality varies greatly from brand to brand and the TP lint can't be helping things either. Amsoil's Ea-BP90 efficiently filters down to the 2-15 micron range without any chance of oil getting around it.

Even still, the bypass filter does not filter all the oil all the time.

Not really again, look at the fuel's value around the world.

Wow, force induction just admitted oil is not abiotic!


No really forced, I totaly thought you hated peak oil theory

__________________
1981 300SD 512k OM603

The topic of the thread is whether a member can use 50% used motor oil without harm to the engine.

Again, discussions regarding whether the cost of fuel is too high or too low are off topic.

Discussions regarding the ignorance of a specific member are in violation of the forum rules.

If you can't seem to have a discussion with a specific individual due to their inability to see the opinions of others, then simply put them on ignore. If you are unsure of how to accomplish this, please contact me via PM.

I've never run it personally, but my inclination is that the fuel filter, given that its entire purpose is to remove things from the fuel stream that are large enough to cause damage - would not allow metal bits above the critical "damaging" size to get through any more than it would let any other fuel stream trash get through.

A good set of precautions would be

1. Let the oil settle a good long time, and when pouring into the tank, don't pour the last inch or so in. Recycle that, it's got most of the settled garbage in it.

2. Maybe consider running 25% instead of 50% to further thin the overall fuel mixture and hopefully let things work a little more smoothly. The car will think it's running cleaner fuel than it will at 50% anyway.

__________________


~Michael S.~
Past cars:

1986 300SDL
1987 300SDL
1982 240D
1982 300SD


Current:

1987 300SDL

Filter, but don't waste much time settling... remember this oil is designed to keep things in suspension.

__________________
'79 300SD
'82 Chevy Chevette diesel

This is interesting, half the forum doesn't even want to run straight ULSD because they don't think the lubricity is adequate; and the other half thinks it's OK to run chunks of metal though the fuel system.