drain oil

[irwinsailor]

Where I live in Holland Michigan the truck leasing companies dump all of the drain oil in the fuel and it is Legal here. I first read in the paper a few years ago about one of the companies doing it. They had a mixture that was more than was allowed by state law and one of their trucks was fined. It was not a big deal but it was something to write about. The paper said that it is a very common thing and was allowed as long there was not enough to cause excessive smoking.

[MidLandOne]

Of course, if it is fine for leased trucks engines then it must be fine for your boat's engine too .

Seems to me you made up your mind long ago that this is what you were going to do so why not just get on and do it . But in order to add to the fund of knowledge please let us know how it goes and also the condition of your fuel tank, etc, as well as the engine in a year or two.

[irwinsailor]

I made up my mind after reading about dumping it overboard earlier today.

I have also been trying to remember what Magazine I read that it was OK to run home heating oil through your engine. It may have been Passagemaker, one expert said that it was Ok and another said that it was not a good idea.

This could be another what anchor is best thread.

[Jentine]

Home heating oil, here in the northeast is #2 diesel. The only difference is the taxes that are paid by over the road users as opposed to no taxes on home heating oil.
By the way, I dump all my used oil in the home heating oil tank and it is burned along with the #2 diesel in the winter. My heating technician told me that the only difference between the furnaces that garages use to burn used lube oils is the gauge of the orifice. 10 gallons of used oil mixed with 1000 gallons of diesel will not effect the operation of my heating system adversely.
I don't think I will be adding lube oil to my engine's fuel supply in the near future. However, if faced with the choice of dumping or burning the oil, I might be tempted to burn it in the engine in small amounts so as to not clog the filters.

[Stranded Mariner]

Burning used oil mixed with diesel in a furnace is not a problem.

Running it through a diesel engine is a different story. Alan already mentioned the carbon and metal particles, but the biggest problem are the basic additives in modern lubricating oils. They give the oil the ability to neutralize acids formed during the combustion. This acid binding property is expressed in the TBN of an oil(Total base number). A lot of these basic additives are Calcium components.

When you burn lube oil in an engine, you risk getting Calcium sulfate deposits on valves, piston crowns, and in the exhaust system (including turbochargers). The ease with which these deposits are formed, depends a lot on the sulfur content of the fuel. Now in the US the sulfur content of diesel fuel is extremely low (by law), so that might be the reason why these truck companies don't really have big problems when mixing old lube oil with the fuel.

I had a case in a diesel power plant once, where the fuel supplier had mixed waste lube oil with the fuel. These were big engines (620 mm bore) on heavy fuel oil (bunker C). There were deposit layers on earlier mentioned parts of up to 1.5 cm thick. The worst part is when they fall off, and into the combustion chamber. It's like throwing grinding stones on your piston or through your turbocharger.

[Alan Wheeler]

Well strangly, last nigh I was sitting with a bunch of 4WDing enthusiests around a camp fire and this very subject was brought up. It turns out that two Toyota owners burn their old sump oil in the fuel. At a ratio of no more than 10%. They both reckon that it keeps the injector tips clean. I made the comment that it was likely the particles in the oil/fuel mix was wet abrasive blasting the tips. But they were adamant that it was OK and they have done many miles on their engines.
OK so from my perspective, that day prior, I had thought that one of these guys engines was on it's last legs it was blue smoking so much. So it turns out the smoke was actually the oil in the fuel.
I don't know, I am still of the opinion it is not good and I certainly wouldn't do it myself. But I can't argue against those that are doing it and are having seemingly no issues. Other than producing smoke that is. This wasn't the sort of group that I could argue about our environment and pollution of our atmosphere, or I would likely get dragged behind a vehicle through the mud.

[MidLandOne]

[quote=Alan Wheeler;141461]At a ratio of no more than 10%.[quote]

We get through about 300 litres of diesel in a year in the boat, 10% of that is 30 litres and an oil change is 6 litres. So 10% would be 5 oil changes.

Now, what would be best for the engine - changing the lube oil only once per year but not burning it in with the diesel, or changing the lube oil 5 times a year and burning it in with the diesel?