Burning Used Motor Oil

[BLeinart]

I've got a friend who is taking used motor oil, mixing it with gasoline at 30% to get the viscosity the same as diesel. Then he filters the mixture to 1 micron, and fills his tank up on his cummins. He has been doing this for close to a year without problem. Now he's using it in a 6. 0 ford. It doesn't seem to smoke any extra. I'm wondering what effect the gasoline will have on the engine, if any. I don't think lubricity is an issue with 70% oil.

 

[fox]

Too much gasoline.

Alittle won't hurt it, but I've been told to stay under a gallon per tank.

I really don't think it is smart with the chemicals in gas.

 

[BLeinart]

Too much gas is what I told him, but now that he's been doing it so long, I question myself.

 

[Joseph Donnelly]

This is a bad idea, in my opinion. Chemically, diesel fuel is a mixture of molecules with molecular weights, boiling points, and burn rates in between gasoline and oils, and far faster burning than motor oil. What you have here is gasoline that ignites instantly, and is then trying to burn the oil fraction that is almost impossible to burn in the environment of the engine's cylinders in the time available. Only marine diesels are designed to use heavy oils, and then usually not as heavy as motor oil. In another year or so, your friend will be replacing his engine, with stuck rings, unbelievable amounts of sludge, and a sludged up fuel injection system. With newer fuel systems having tighter clearances, the problems will surface sooner and be even more severe.

 

[snuff]

holy$##@@#$@#

on the other hand, hey sounds like your buddy gets to buy a new engine down the road cool



yea this can't be good. used oil that has been throughly filtered and good diesel then i would say go for it.

 

[snuff]

also we would like to see pics of the carnage the gas caused...

 

[PRout]

Interesting. . Thanks for the input Joe. I've been hoping to see a post like this for a while since I know very little about this field. Looks like I'll be recycling used motor oil, and stick with running at least a small percent of biodiesel for lube instead. (depending on prices and climate the truck will be in - warm, cold, etc. ).

 

[The patriot]

I've used up to 4 gallons of highly filtered used engine oil in a full tank of diesel. Only in the hot summer months.

I wouldnt use gasoline to lighten up the viscosity. I'd rather heat it.

JM. 02

 

[Matt400]

Hey BLeinart,

What year truck was your friends Dodge?

 

[AABEN]

Gas is hard on fuel pumps I thank this might be the first to go. He is saving money now but I thank it will cost him down the road!!!BIG MONEY

 

[MAllen1]

Back when I worked on diesels, professionally, I would mix oil (I would've preferred atf). But, I would not mix more than 1 qt. for every tank of diesel fuel. Like I said earlier, though, I like using atf before oil---its thinner than diesel oil and the truck over the long run would not have as hard of a time. As a side note, though, I wouldn't this but 1-2 times every oil change---maybe up to 3 times with this new fuel we are running,

 

[GDMRTN]

I been runnin about 15 - 20% gas with waste oil in my '99 for long time now. Never a problem. With the money I've saved in fuel I can afford to replace my entire injection system.
Be warned- If the gas content is too high, it will vaporise in the injector lines and the truck will die. Don't ask me how I know.

 

[BLeinart]

Its an old 1st gen, 1992 or 1993

 

[BLeinart]

Hey GDMRTN, how long you been running that mix, time and miles?



As far as burn rates, he showed me soem of his mixture burning compared to diesel and it looked pretty much the same. The gas mixture was not explosive like you might think it would be

 

[MMeier]

As far as burn rates, he showed me soem of his mixture burning compared to diesel and it looked pretty much the same. The gas mixture was not explosive like you might think it would be

How did he do that??

 

[GDMRTN]

Time? About 2 years. Miles are unknown. Approx 20 - 30K a year. The gas isn't as flammable as you'd think when mixed with oil. If you're too scared of it, just put 3 gallon of oil in a bucket and dump a gallon of gas in and see what it looks like and how it burns. It turns out to be very close to #2 with a gas smell.

 

[The patriot]

When I had my big truck, guys would mix gasoline with diesel during the winter, I suppose to stop gelling.

I never did it.

 

[betterthanstock]

Fuel has "average" properties, and refiners do similar blending to achieve average cetane, octane, etc.

No fuel is one pure molecule. Gasoline has about 300 different length molecules, and that's why when it goes bad, it clogs up carburetors.



I think 30% in the summer is a little much (and more expensive than it should be) but if it works, great.

I'd be more weary of the HPCR engines though.

Vapors from fuel tank are hazardous though, and diesels have no vapor recovery.

 

[Grizzly]

I've got a friend who is taking used motor oil, mixing it with gasoline at 30% to get the viscosity the same as diesel. Then he filters the mixture to 1 micron, and fills his tank up on his cummins. He has been doing this for close to a year without problem. Now he's using it in a 6. 0 ford. It doesn't seem to smoke any extra. I'm wondering what effect the gasoline will have on the engine, if any. I don't think lubricity is an issue with 70% oil.

That's kind of like drinking and smoking heavy for 20 years and think your health is going to be okay by the time your 50. WRONG!

 

[Vaughn MacKenzie]

The main problem with gas is the gum & varnish it has, which tends to build up as deposits on injector tips and possibly rings. Also gas burns hotter, glazing the deposits onto the injector tips. I would give another 100F margin on the pyro to avoid piston damage or injector tip damage.

With that said, to date I've burned ~250+ gallons of gas over the last year mixed with veggie oil (the "DSE" fuel). I pulled the injectors not long ago and there was some hard crusty deposits that were not easily removed but the buildup wasn't that significant. My feelings are there probably isn't going to be enough deposits around the rings to be a concern but time will tell.

CJ Hall has burned hundreds of gallons of gas in his 3rd Gens with no issues to date, I think he goes over 15% in the winter. I've gone almost 20% gas in the winter, running about 8% at every fillup during the summer.

Vaughn