Fuel its dark, filters very dirty....whats the problem?

A company I worked for did that. They had about 50 trucks, and the old oil coming out of the trucks went into the fuel tanks. According to our boss man whom we called ‘Slide Rule,’ it saved him money of fuel.

 

I was told by a 40+ year veteran with a 1.6 million mile truck that he put a gallon of used oil in each tank monthly. His reasoning (not mine) was that with the detergents and additives that are in today's fuels tend to keep the valves and other parts dry. The addition of oil helps lubricate those parts and makes them last longer.

Now, that is just HIS way of doing things and HIS reasoning.

 

Cat has a good fuel treatment, used it in all equipment and trucks. Our bulk fuel tanks got algae ( diesel sludge). Took a couple of treatments.

 

I recall reading an article not long back that gasoline now days is to dry and causes many troubles in the vehicles that use gasoline. I suppose it may be happening to diesel fuel too.

 

That was the fear with ULSD, that it wouldn't lubricate as well. I guess it depends on what's added into the fuel before sale by the vendor.

Adding used oil probably isn't a good idea if you have an EPA2007 and up engine. DPF replacements aren't cheap.

 

Well, it depends on how old the filter is. I guess 40k+ mile fuel filters would look black even if there was no algae

 

Cummins years ago used to sell a oil blender . You put a fitting in place of the drain plug, and it would draw the oil out . You also had two hoses , one drawled fuel and one retuned the blended fuel back. Of course this was decades before electronic injectors. Burnt used oil as fuel , saving fuel cost and disposal cost/headaches. Machine paid for its self in its first year. Only waste was the used filters.

 

Gee,unless the ole boy tried his hand at making some black diesel out of old waste oil,I would suspect Algie.Killem actually Works.

 

Just a note, if injector seals leak slightly,seals between diesel and high pressure oil, there will still be enough oil pressure on oil side for engine to run, but oil is dumped into diesel tank through diesel return line. It will cause dark diesel and the engine will run fine. If engine slowly uses oil and you don't see signs of leaks, this may be your culprit.