Two-Stroke oil
 

After flipping through all the past Diesel threads, I noticed nobody has mentioned using 2-stroke oil as an addative...

I have been running it for about a year and a half. Mainly for extra lube in that damned VP Cummins but about a year ago upgraded to Common Rail (still CTD). I use a 128:1 ratio of diesel to 2-stroke and consistently see over 1mpg improvement with fuel mileage. The truck is by no means stock but I have also run 2-stroke in my dad's bone stock '07 (5.9) and he sees a 1-2 mpg improvement as well.

Just throwing this out there. Not saying everyone should try it but is has been working for quite a few....the trend at Cumminsforum.com is it is hit or miss. Some trucks see an improvement others nothing. It has been show that too much 2-stroke will cause severe power loss.

Here's the long thread about it.

Two stroke oil is designed to be lubrication in a liquid/mist form for lower ends and cylinder walls. Using it as an additive in a diesel's fuel system does not allow it to be used for these properties. The combustion process during diesel injection burns the oil leaving only carbon, not lubricant, before it reaches friction surfaces.
There may be some benefitial lubrication properties for the injection pump, but if the pump's inherent friction were such that a minimal dose of oil resulted in the vehicle seeing a 10% mpg improvement (presuming that it averages somewhere between 10 and 20 mpg) then the pump would have worn itself out within a few hours of use without oil. Think of it this way: if one brake were dragging, producing a friction load, sufficient to drop mpg by 1 mpg, how long would that brake last? Bumping your mileage by 1 mpg is equal to removing that same amount of friction.
Your improvement in your truck I attribute to a placebo effect. You are, perhaps subconciously, driving differently enough to change your fuel economy.
The reported improvement in your dad's would be more believable only if you didn't tell him which tanks had the oil and which didn't, (a 'blind' test), and the average of all tanks with oil were 1~2 mpg better than the average of all tanks without.
Those are probably the two main reasons you don't see more reports here. There are doubts on its effect on the engine and there are doubts about its effect on the driver.

Diesel, as you should know, since you are making these comments, is used as a lubricant for many pieces of the truck. The lift pump and injection pumps as well as THE ENGINE. Why did everyone see a significant drop in fuel mileage when they switched to ULSD?...maybe because less sulfur = less lubrication. Two-stroke oil is putting that lubrication back into the fuel. No placebo here.

And yes, when I dumped it in my dad's truck I didn't tell him. Just asked him to let me know what his mileage was after that tank.

Sulfur (note the spelling) is a cutting agent added to machining oils to assist in the process of material removal. Sulfur is not a lubricant.
The process of removing the sulfur has the unfortunate effect of also reducing the latent heat content of the fuel. THAT is the reason many have noted a drop in fuel economy. Adding sulfur back in to the ULSD will not restore the BTU content.
Diesel fuel, unless there is something drastically wrong with your engine, doesn't get past the piston tops. Please do tell how it can lubricate when it isn't present in other areas? Since it can't lubricate the valvetrain, the crank journals, the connecting rod bearings, and other moving engine components, then the only lubrication is can provide is to the lift pump and injector pump. Obtaining such a dramatic mileage improvement as you claim from these two engine components alone is beyond ridicule.
And one tank (you wrote: "that tank") isn't an average.

lug nut, how do you explain the failure of so many injector pumps since the removal of sulfur? and cutting oil serves more purpose than you give it credit for, try running a drill press without cutting oil, and see how long your bits last.

i have added it to my truck (gas) and it idles smoother

I'm not going to argue with you. You are skeptical. Good for you. I didn't post this up for you, then. There are...probably well over a thousand Cummins' running 2-stroke oil...certainly not because it doesn't work. Please go away.

BTW, I didn't directly say the sulphur/sulfer (often interchanged) was THE lubricant in diesel but it certainly IS lubricating.

You are rather incorrect in that statement, Sulfur is in cutting oil for the same reason that is is in gear oil, because it is such a good high pressure lubricant.

and the sulfur is way the stinks Sooooooo bad when you burn a rear-end ??

I dare say many more injection pumps have failed on high (5000+ ppm) sulfur fuel than have failed on low (500 ppm) or ultra low (<50 ppm). I base that assertion on the mere numbers of diesels and the number of years that each type of fuel was in use. I know that I've had zero pump failures on zero sulfur content fuel since 2001. Sulfur content, based on that empirical evidence should be eliminated completely, no? Others have had pump failures with 5000 ppm, 500 ppm, 50 ppm, but I've had none with 0 ppm?

I use cutting fluids. and when I need to have a perfect cut I use the sulfur content cutting fluid. When I want to lubricate I don't.


Sorry to dissapoint you, but it it not my sole purpose to defer to your desire. I made my opinion known and there is no further need for me to beat it to death. I'll shut up until another poster starts another thread on the same subject.