Adding Used Motor Oil to Diesel Fuel?

[Hunky Dory]

Just a interesting note. I own a restaurant and my used cooking oil is picked up, filtered, heated to drive off moisture and used in a transport. Diesel in western Canada is $1.20 liter. or approx. $3.25 US/ gal

[a64pilot]

Originally Posted by DHHerndon

Rather than adding engine oil, a much better additive would be to add biodiesel. biodiesel has very high lubricity and also burns cleaner than regular diesel. Biodiesel up to 20% can be added to almost any diesel engine old or new. A 20% biodiesel is called B20 and can be purchased as B20 or B100 and then mixed into your tank.

It is very good and I would run it in my truck when I could find it which wasn’t often. This is Bio Diesel made from soy now that we are talking about. There are many ways to make Bio Diesel that is completely different and some I don’t want near my engine.

However I don’t think bio from soy stores very well, and I’m nearly certain it’s bad about growing bugs, so it may not be good for boats that don’t burn much fuel and may only fill up once a year or so, but for those that burn fuel quickly, and especially if they have a common rail motor soy bio is excellent, even if you can only get 5% it helps with lubricity a lot.

But is think the point here with burning used motor oil is the theory of getting free fuel and not having the hassle of disposing of it, just pour it in the tank and go.

[MikadoII]

The Steam Tug Wattle, in Melbourne Australia, runs exclusively on used oil which has been through a pretty impressive centrifuge. The residual muck that comes out of the centrifuge is phenomenal. The boiler injector is a wee bit different to a diesel injector.

[Cadence]

Originally Posted by a64pilot

It is very good and I would run it in my truck when I could find it which wasn’t often. This is Bio Diesel made from soy now that we are talking about. There are many ways to make Bio Diesel that is completely different and some I don’t want near my engine.

However I don’t think bio from soy stores very well, and I’m nearly certain it’s bad about growing bugs, so it may not be good for boats that don’t burn much fuel and may only fill up once a year or so, but for those that burn fuel quickly, and especially if they have a common rail motor soy bio is excellent, even if you can only get 5% it helps with lubricity a lot.

But is think the point here with burning used motor oil is the theory of getting free fuel and not having the hassle of disposing of it, just pour it in the tank and go.

You may have nailed it. It's not what diesel is made from. My father would say olive oil would work. It's those little pieces 0f metal in the used oil. Is the filtering or polishing worth that qt. of oil, I somehow doubt it.

[Kreycik]

Have you considered an electric conversion? We replaced our Universal m25xp engine with an electric motor and now have no problem with diesel oil waste, diesel spills, oil spills, diesel odor, noise and the nagging sensation that diesel powered sailboats, intended to be powered by the sun, are contributing disproportionately to changing our climate.

[parkstone bay]

To revert to the original question; "would it work?". The short answer is "yes".
But, the big question that it then raises is "Is it worth it?" (There's the point that the lube oil ISN'T intended to burn in an IC engine (indeed, modern high-end are specifically intended NOT to degrade under high temperature and pressure); there's the point that it is contaminated with micron-size metallic particles from the bearings and wearing surfaces; there's the point that it's contaminated with combustion products, which are in fact acidic; there's the point that you'd probably not be able to use much more than 1:100 (like a modern 2-stroke petrol/gasoline engine) without noticing a degradation in performance or emissions; .... the list goes on). So, the long answer is "yes, it would work, but don't do it".
Interestingly, I have often wondered whether it would be worth adding new, not used, inexpensive lube oil to diesel in a proportion of say 1:1000 to improve lubricity.

[seabreez]

[QUOTE=CapnCrunch;3026160]I have found casual mentions of the practice but can's seem to find a full thread on it. I gather that it not a recommended practice for newer engines but I haven't seen any negative comments about doing it with older diesels.

I also gather (again only casual mentions) that the used oil should be kept to around 1% of the fuel volume.

Does it cause operation problems?

15 years ago, approximately, I was repairing many diesel engines and at one time when the fuel quality was changed to meet some regulations it dried up gaskets and O rings in some fuel injection pumps. To correct this situation many guys would add automatic transmission oil (Dextron) to the fuel tanks. I believe it was one litre to a hundred mix and that would stop the leaks. The transmission oil would lubricate the O rings and make them swell up and seal. That was my understanding. Four years ago, I was in Florida and cycling along the A1A and came along a dock where there was three diesel mechanic repair shop trucks. I joked with one person that it must be a big problem to have three trucks here. The person asked if I knew about diesel engines and I replied yes. I was invited aboard and sure enough there was a fuel leak at the injection pump. I mention to add a piece of hose and drop it in a jerry can and that would stop the leak in the bilges. Then when the can would fill up, just dump it back in the fuel tank. The mechanics and the owner were surprised at my solution but they did it and vacuum cleaned the fuel mess in the bilges. Then they added transmission oil in each tank. A few days later the fuel leak stopped. The owner phoned me to thank me and offered me a trip for a cruise with him...

[OneHullPaul]

Nice deflection Grandad.

Originally Posted by Cadence

If you can get me to be a boomer please let me know. My grandsons are boomers. [emoji2]

[Cadence]

Originally Posted by OneHullPaul

Nice deflection Grandad.

Paul, deflection I don't know, more the truth. I'll leave it to the younger generation to solve it. We "the old lady" and I recycle everything they will take. Drive a two ltr. car and have a heat pump for the HVAC, replaced when the old still worked but no longer had the highest efficiency.
I hope someone finds the ultimate solution.
When is it we can no longer feed the world population? One more thing to consider for mankind.

[lord at sea]

Originally Posted by OS2Dude

Perhaps you should start. Yes, the EPA can be overly picky about things. No, your vessel by itself does not make much of an impact on the would wide environment. But is everyone pollutes because it is easier, cheaper, and their 'outa-sight, outa-mind' mentalities then the impact is much greater, especially on the local environment.

Burning oil in fuel has no advantages other than a way of getting rid of it. that said if you want to increase your fuel economy you should place a contact filter in line with your blow by (PVC) system that way you actually remove excessive oil and allow the un-burned fuel oil to be returned to the intake, since most of the blow by comes from the inherent problem of air and fuel getting past the rings into the crank case, this removal of engine oil increases more complete combustion and since your not burning engine oil you get less carbon build up on the valves and exhaust system, EPA doesn't like that either since the more complete combustion you get the more nitros oxide considered a GHG. and in the process you get more power and better fuel economy.

[lord at sea]

Originally Posted by Boatyarddog

Thanks!
Good Folks Everywhere
Keeping oil out of the air and Oceans IS and has always been most important,
4 stroke technology was developed for that purpose.
No reason to back up on preventing pollution.
Cheers,
SV Cloud Duster

while your intentions are some what noble, may I remind you that if the situation was as dire as you think (Most) the governments of the world would have taken the real steps to protect the world from this man made catastrophic problem long ago, when you boil it down to who controls the climate it's water vapor and the sun who are in control, but since you can't control it or make money off of it carbon is the next best thing, but only if you don't take water vapor into the house of GHG's. if people took the time to check it out, in stead of getting on the climate wagon. we wouldn't have a problem. you think of green land as being covered with ice, well how do you think it got it's name originaly, yes it was GREEN.when discovered by the Vikings some 800 yrs ago. but your right that we shouldn't pollute our life blood, nor should we panic while the earth does it's climate change as it has always done.

[lord at sea]

You won't feed the world by reducing Carbon dioxide, you have to increase it. the levels of carbon have never been so low in history. it's only at about 400 Ppm now, when during the Jurassic era it was over 7000 Ppm and the temperature was around 21 C.

[capnorv]

I used to dump old oil in the tank, but not anymore. I use it, like all my waste plastic, to start camp and waste fires. As the famous Dr. Lovelock said "the only good plastic is burned plastic". I take that to include oil too, not much difference. Is it legal? No, but I'll bet our President is thinking of making it so. More CO2= paradise up here in the Pacific NW, at least in my lifetime. LOL

[4palmer]

That is absolutely not a good thing to even think about. Which is heavier Oil or Fuel? The reason you are taking out the old oil is that it is dirty or has lost its viscosity to protect your engine bearings and ring. The whole Idea of having clean fuel, clean tank, clean primary filters, clean secondary filters is for one main thing>>>>>>>>keeping your injectors clean. A millimicron of a chunk of carbon can kill the injector costing you lots of cash to clean or ending up on the rocks when you need power. No No NO NO.

[Boatyarddog]

Originally Posted by capnorv

I used to dump old oil in the tank, but not anymore. I use it, like all my waste plastic, to start camp and waste fires. As the famous Dr. Lovelock said "the only good plastic is burned plastic". I take that to include oil too, not much difference. Is it legal? No, but I'll bet our President is thinking of making it so. More CO2= paradise up here in the Pacific NW, at least in my lifetime. LOL

I had to breath for a minute or two before commenting on this disturbing post.
Is it LEGAL?
Really doesn't matter!
ITS JUST PLAIN WRONG!
Others in The PNW, know the thinking of gross and uncaring polluters.
This posting is the Antithesis of this understanding that the ENVIRONMENT is PARAMOUNT to the survival of ALL life on this planet.
You live in one of the STILL most pristine areas in the World and YOUR ATTITUDE IS ATROCIOUS.
Please save these comments for a more appropriate venue, TRY FOX NEWS FOR AN INTERESTED PARTYS TO SHOVEL THIS CRAP AT.
SV Cloud Duster