Yes, you can run used motor oil in your car!! - PeachParts Mercedes-Benz Forum

billrok · #1 05-01-2003, 12:49 AM

The giant Caterpillar Diesel generators at work contain 110 gallons of Delo 400 15W 40 each. Every year the oil is changed with about 9 hours of running time on the oil. I have the guys set aside a 55 gallon drum for me to use in my beloved 85 300SD. Since I have plenty I usually change my oil every 2,000 miles or less. I change filters every other oil change. I initially tried it for 1,000 miles and sent in a sample for oil analysis as I was worried about the degradation of the additive package sitting in the generator for a year. My fears were completely unfounded as the oil test results came back absolutely perfect in every category. I know I can get Delo cheap at my local Auto Zone but even at $6 bucks a gallon I'm way ahead of the game and my Benz loves the attention. Comments please??

Lycoming-8 · #2 05-01-2003, 01:22 AM

That is a hoot. You should have them save it all and then you would eventually be set for life. Or at least have enough for much higher mileage, especially if it ever begins to burn a little!!

P.E.Haiges · #3 05-01-2003, 01:22 AM

Billroc,

I see nothing wrong with what you are doing. You are also conserving resources.

And after the oil comes out of your engine you could filter it and use it for fuel by making maybe a 5% mixture with your Diesel fuel in warm weather.

P E H

billrok · #4 05-01-2003, 01:51 AM

The only downside of my many oil changes is taking the used stuff to my local garage to recycle it. If I could figure out a way to filter it, I think I would burn some in my car.

#5 05-01-2003, 06:47 AM

billrok,

P.E. just told you a way.

I would first filter it through a very fine filter. There is a huge sock filter that you can buy at the bio diesel website that would work great for this.

Good luck,

gsxr · #6 05-01-2003, 12:07 PM

Running used motor oil, filtered or not, in your fuel tank in large quantities is not necessarily a good thing to do. At least not to a car you care about. I have a VW Dasher Diesel beater that I wouldn't think twice about feeding used/filtered oil as fuel, but I'd never put it in my MB. There are fine particles that you can't filter out, which don't do nice things to injection pumps and injectors at 2000psi. It's up to you, though. BTW, I think re-using the 9-hour Delo in your crankcase is fantastic!

R Leo · #7 05-01-2003, 02:21 PM

Centinel is a Cummins-designed system for used oil management in large diesel fleets.

http://www.cummins.com/au/pages/en/products/genuinepartsandservices/extendedlifeproducts/centinel.cfm

gsxr · #8 05-01-2003, 03:01 PM

Thing is, Cummins and MB diesel are different designs (direct injection vs. indirect, etc), different injection pumps, etc and they don't mention the dilution rate. Small amounts over time should be less of a problem, but there was one guy here who wanted to run gallons of it per tank.

R Leo · #9 05-01-2003, 11:16 PM

Most direct injection diesels (the VW TDi being the exception to the rule) require more refined fuel stocks ie: #2 fuel oil to run reliably. Cummins engines may be either DI or IDI depending on age. CENTINEL equipped engines burn their lube oil at an extremely low oil/fuel ratio which reduces mixed fuel issues.

OTOH, our good 'ol OM616 and 617s are indirect injection (IDI) engines with in-line mechanical IPs all of which are highly tolerant of widely varying quality of fuel stocks. The IDI Mercedes OMs are found all over the world running on fuel that is far from the ideal.

Regardless of source, the alternate fuel used should be filtered to around 10 microns and be able to remain liquid at low temperatures for reliable operation.

For comparison, disturbing specs found on the WIX filter site (http://www.wixfilters.com/productinformation/gff_oilfilters.html) state:
"Particle size retention is the measure of the degree to which the filter can retain particles of various sizes. Wix has developed optimum particle size retention quality in filter media by extensive engine wear tests including exhaustive testing of filters used in racing, and sophisticated laboratory tests. Wix media in the automotive full-flow oil filter is able to trap and hold essentially all the contaminant particles larger than 25 microns. (A human hair measures approximately 70 microns in diameter. An object that is 1 micron in size is .000039 inches in diameter.) Our filters also capture a high percentage of even smaller particles."

Only 25 microns? Geeze!

AlsoCheck this alternate fuel thread:
http://www.peachparts.com/shopforum/showthread.php?threadid=57481

Regards,
Randy Leo

whunter · #10 12-29-2005, 06:01 PM

Quote:

Originally Posted by R Leo

Most direct injection diesels (the VW TDi being the exception to the rule) require more refined fuel stocks ie: #2 fuel oil to run reliably. Cummins engines may be either DI or IDI depending on age. CENTINEL equipped engines burn their lube oil at an extremely low oil/fuel ratio which reduces mixed fuel issues.

OTOH, our good 'ol OM616 and 617s are indirect injection (IDI) engines with in-line mechanical IPs all of which are highly tolerant of widely varying quality of fuel stocks. The IDI Mercedes OMs are found all over the world running on fuel that is far from the ideal.

Regardless of source, the alternate fuel used should be filtered to around 10 microns and be able to remain liquid at low temperatures for reliable operation.

For comparison, disturbing specs found on the WIX filter site (http://www.wixfilters.com/productinformation/gff_oilfilters.html) state:
"Particle size retention is the measure of the degree to which the filter can retain particles of various sizes. Wix has developed optimum particle size retention quality in filter media by extensive engine wear tests including exhaustive testing of filters used in racing, and sophisticated laboratory tests. Wix media in the automotive full-flow oil filter is able to trap and hold essentially all the contaminant particles larger than 25 microns. (A human hair measures approximately 70 microns in diameter. An object that is 1 micron in size is .000039 inches in diameter.) Our filters also capture a high percentage of even smaller particles."

Only 25 microns? Geeze!

AlsoCheck this alternate fuel thread:
http://www.peachparts.com/shopforum/showthread.php?threadid=57481

Regards,
Randy Leo

Hello Randy
Could you please make this data a seperate thread?
The micron filteration level of our fuel filters is an important topic.
Thank you.

Old300D · #11 01-02-2006, 02:24 AM

Quote:

Originally Posted by gsxr

Running used motor oil, filtered or not, in your fuel tank in large quantities is not necessarily a good thing to do. At least not to a car you care about. I have a VW Dasher Diesel beater that I wouldn't think twice about feeding used/filtered oil as fuel, but I'd never put it in my MB. There are fine particles that you can't filter out, which don't do nice things to injection pumps and injectors at 2000psi. It's up to you, though. BTW, I think re-using the 9-hour Delo in your crankcase is fantastic!

What sort of "fine particles" can't one filter out? Are you talking about steel? The insides of the IJP and the injectors are steel, but most debris from motor oil is bearing/ring material, substantially softer than steel, isn't it? And at less than 1-2 microns, how much is going to cause a problem?

dgreenhouse · #12 01-02-2006, 08:14 AM

hhmmm, let me think about that
1 - how bad can small particles of metal be to an engine??? that question immediately stops me from using used engine oil as fuel in my benz

2 - how bad can sub-micron particles of metal be for people breathing them in from the exhaust? that question immediately should stop you from using used engine oil as fuel in your benz. if you are looking for cheap/clean fuel then pick up some WVO and use that...

Old300D · #13 01-02-2006, 11:54 AM

Quote:

Originally Posted by dgreenhouse

hhmmm, let me think about that
1 - how bad can small particles of metal be to an engine??? that question immediately stops me from using used engine oil as fuel in my benz

2 - how bad can sub-micron particles of metal be for people breathing them in from the exhaust? that question immediately should stop you from using used engine oil as fuel in your benz. if you are looking for cheap/clean fuel then pick up some WVO and use that...

It was a simple set of questions. It should be obvious that I already run as much biodiesel as my local temperature will allow. But I have some UEO that I filter with a 1 micron filter, and run one gallon per tank.

It should be obvious to most that 1 micron filters motor oil much more effectively than an engine oil filter. Any residuals passes though the fine tolerances of the injection system once. I've seen engine oil analyses, and there is not much metal, at least on my vehicles, and I would never use any else's UEO.

So tell me again how I am doing untold damage to my engine and the environment. I'd be doing more simply by running "WVO".

#14 01-02-2006, 12:01 PM

Why don't you have them save ALL of it for you and you sell it locally to other diesel owners real cheap. It would be some good change. Have those guys bring back their "used" oil when they get done, then you filter their waste oil and run it as fuel! After they bring back their "used" oil you give them a $1.00 discount and seel them more of your oil.
MONEY, MONEY, MONEY , MONEY!!!!!!!!!!!!

#15 01-02-2006, 12:04 PM

Quote:

Originally Posted by Old300D

I'd be doing more simply by running "WVO".

Huh?