Could anybody tell me how they go about mixing used engine oil to put back into the fuel tank. What additives do you use and what ratios.

 

I would never do that with these engines. THose days are LONG OVER>..

 

I second!that ran 50/50 filterd to two microns in my 99 could not make me do it in the 07.5 6.7
I did do it for about 6 months in the 07 5.9 got sceard when I lost an injecter
dont know if it was related or not

 

As a Industrial Mechanic I do not recommend that, your oil filter does a good job filtering out the metal filings that are worn off your engine, as well as soot and other forign materials, but when you do a oil drain on you engine there is still going to be forign material suspended in that oil. I know we are only talking about particles that are measured in microns but think of your injectors and fuel pump.

 

my other question is why on earth you you want to ever do that? this is the first time i have ever heard of this practice.

 

This has been talked about alot in the 12 valve forums. Cummins says its OK to run a 5% mix in your fuel. Now this is on a 12valve.

 

What it the gain by doing this? tony597fitter i'm a proud union man myself local 1178

 

I would so no to that in that truck. maybe in an old tractor. Or just take it to autozone its free to get rid of it there.

 

Heck,
I dont do this in my truck. I was just stating that some people on the 12 valve forum do this. If Cummins says its OK to do, then why not. Guys say it makes up for the lack of lubricating properties in the ULSD.
Also, these are Cummins OIL BURNING ENGINES!

Remember, different strokes for different folks.

 

If your looking for better lubricity in the fuel, plus clean the injectors i have used new auto transmission fluid. but i agree different strokes for different folks.

 

Don't do it in the new trucks, the 12 valves can handle it, but I would still filter it really well first.

 

In my truck for extra lubricity I run a mix of Biodiesel. I usually run at least a B20. I have run 100% too. It really quietens her down.

 

I have so far always run the drain oil through the engine fuel system. That is including my '99 and my red top N14 cummins. I cannot speak and will not for the later engines only because I have not experience with them.

The question was asked, why? More power, more economy, near $3 a gallon ;put in the tank. You do have a fuel filter on your truck don't you? Now I only burn my own oil but years ago I used to buy it from the local gas stations and burn 10%. I would not go over 5% that Cummins recommended though.

Look at it another way, at each oil change on the Freightliner I get $30 free fuel. Never had it affect my fuel filters negatively. While I am eating a couple of steak dinners on the road, I will think of you wasting that money.

You northern owners could do something else too. Purchase some #4 heating oil, cut that into the tanks, just not on the engines for ulsf. What are you tryiing to accomplish? More oil base for more btu's.

 

The question was HOW to do it, not wether it should be done. The method is to just pour it in the tank. Mixing before pouring is not needed. Filter it first if you want to.

It is controversial. I've done it a lot in other engines and in my 1st gen, and it's been a very good idea. Not in my Common Rail, but partly because I don't have the same access to the oil as before (and some concerns). I'd love to have someone show some actual damage that was caused by burning waste oil. I haven't seen any problems, but a lot of people are ready to say what a bad idea it is. Show me, please.

Check the thread in the General / Fuels section.


John

 

Just doesn.t seem logical to me to use this practice, I also drove truck for a few years and tried lots of fuel additives, and the best one I used was howes, when you are running you truck at -40deg c the last thing you want to do is thichen your fuel. I want anti gelling properties added lubricity and injector treatment, plus the biggest thing I saw with the fuel additive was fuel mileage, 5.5 to 7.0mpg running in canada, more in the U.S and my trucks ran good, never froze the fuel system in winter,I never fueled when a load of fuel was being delivered to the truck stop. I had a 370 m11 cummins, 470 red head cummins. the 475 isx cummins which gave me lots of fuel filter grief.

I'm not saying mixing of waste oil in the fuel is a negative thing but for the sake of saving $10 on a fuel additive, and mixing waste oil it in the fuel, and running it in a $30 000 class 8 engine or $10 000 DC engine, all i can say is it's quite a risk to take when it's time to talk to the service manager cause there all the same quick to point their finger at the customer.