My time is worth more to me than to mess with burning used oil but the Cummins Centinal system has been used for billions of miles.
The Centinal System allows engines to go 500k miles between oil changes and 100k miles before changing the oil filter. The Centinal system removes a small amount of used oil and sends it to the fuel tank. The used oil is then blended with the fuel and burned during normal combustion. Simultaneously, Centinal adds the same amount of new oil from a make-up tank into the engine.

 

I added about 2 gallons of used motor oil to my nearly full tank the other day. The only thing I have noticed is that my fuel gauge went a little higher. Of course my brother the "diesel expert" said it was stupid to put used oil in my tank and that it would ruin my engine so I figured it was OK. :-)

Edwin

 

Do a search on black diesel and you will find members that have been burning waste oil in first gen trucks since they were new. I started doing it awhile back to offset the price of fuel a little in addition to lubing the fuel system. The truck runs better and quieter with it in the tank. The wife can even here the difference in the way the motor sounds! The main resone that you change oil is that the additive package breaks down over time. The additives are what you dont want to burn as they can clog injectors.
On another note burning transformer oil is bad!!!!! Some has the potential to contain PCBs. Real nasty stuff that causes cancer.

 

I did not know that about the transformer oil, I dont think they do it to often nowadays. Hey thanks for the info. my dad gets the same results in sound out of his 6.5 chevy motor. His will quiet way down. Not to get off topic, but wasn't the first diesel made to run on peanut oil? please correct me if I am wrong, but I thought i read about this somewhere. Thanks
wheelo

 

One thing you need to be careful of running used oil is if your tank ever gets dipped and is any color other than clear or green they will test it to make sure it isn't offroad fuel. They will find it is used oil.
If you live in one of several states where it's illegal to burn used oil you could be in for a really big fine.

 

A lot of 2-cycle oil has a red dye in it so the dipping thing could be a problem there also.

 

Yeah, I noticed that, so 1st couple times I used 2cycle, I made sure it was the blue stuff.

 

How much 2 stroke oil are you guys talking about running per tankful?