I have a 78 300D (nat. aspirated) and I have been kicking around running straight wvo but due to the climate in the winter and my frequent short trips around town this option never seemed worth it.

I then read of people who blend used motor oil with diesel as a source of cheaper fuel (as well a way to reduce reuse recycle). This of course made me nervous because a lot of the reason diesels use so much oil is because of all of the soot. I considered the possibility of filtration as many do and while it seemed possible and likely to not adversly affect engine life I never felt comfortable enought to actually try it.

At work however I have access to large amounts of used hydraulic and vacuum pump oil. The hydraulic oil is used in hydraulic presses and the vacuum pump oil is from a cnc laser. both of these oils are just as clear coming out the machines as they are going in. They have die in them to make then a yellowish color. So to make a long explanation short I have been thinking about running this oil instead of fry oil because you do not have to wory about it gelling up, and instead of used motor oil due to the fact that hydraulic oil has VERY little if any suspended abrasive particles in it... in fact if it did have contaminants like used motor oil the cylinders would wear out.

I ran a test where I ran the motor on a mix of used hydraulic and vacuum pump oil and diesel and the motor seemed to run a little smoother at idle. The rpm's dropped a very small amount. The most concentrated mix I tried was 80% used oil and 20% diesel. So I am not asking if it will run on this sort of oil I'm just inquiring about any possible problems with the injection pump long term. If I understand correctly the injection pump and the injectors are what most people are worried about when alternative fuels are run.

Has anyone run used hydraulic oil? Is there reason to be concerned about the longevity of the fuel system?

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'78 300D 85,000 original miles drive her daily

Several folks run automatic tranny fluid in their fuel, though not nearly at 20%. We put about a quart of AT fluid in our humvees each fillup because the diesel really isn't diesel (JP4) and this added some lubrication to the fuel system. I add about 1 pint of Diesel Kleen per fillup, but if I had unlimited access to hydraulic fluid, I wouldn't hesitate to substitute. I certainly am going to stay away from 20% hydraulic fluid only because I don't want to know the outcome is bad!!

What is vacuum pump oil composed of? What is a cnc laser? You aren't talking about some kind of silicone oil are you?

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Palangi

2004 C240 Wagon 203.261 Baby Benz
2008 ML320 CDI Highway Cruiser
2006 Toyota Prius, Saving the Planet @ 48 mpg
2000 F-150, Destroying the Planet @ 20 mpg



TRUMP .......... WHITEHOUSE
HILLARY .........JAILHOUSE
BERNIE .......... NUTHOUSE
0BAMA .......... OUTHOUSE

vacuum pump oil is simply a very low viscosity oil (5 or 10 weight). A cnc laser is like a cnc plasma cutter or a wire edm machine only it cuts sheet metal with a laser beam.

I did not run at 20% oil I did a test at 20% diesel. I don't understand the difference between this and veggie oil. "Diesel" engine are really oil engines and diesel is the oil of choice. Does anyone have any real reasons why not to run it? Anyone have experience using hydraulic oil as an alternative fuel?

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'78 300D 85,000 original miles drive her daily

If I had free acess to that much oil, you can bet it would be in my tank. You arent anywhere near NC are you?

-OB
81 300D "Melba"

Nowhere near NC. Well I beleive that settle it then. I'm gonna try it and keep a close eye on my filters and fuel milage.

I'll start by running about 5 gallons of 30% oil and 70% diesel and work from there.

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'78 300D 85,000 original miles drive her daily