Two Cycle Oil In Fuel

[Roy W]

In reference to my post "LLY Rough Idle" I narrowed my problem down to the FPR, so I added a quart of 2 cycle oil to my next fill up. After the second fillup using only a pint of oil, my idle smoothed out, so I assume it got to the FPR and lubed it. Since then I have been added a pint of two cycle oil on each fill up (16 +/- gallons) and my idle is still smooth. My question is: are there any long term effects of adding 2 cycle oil at each or maybe every other fill up?

[Heartbeat Hauler]

As long as you are using a good quality 2-stroke oil the long term effects will be a well oiled fuel system.

Having additional lubrication in your fuel is a good thing as far as I am concerned, and the 2-stroke oil is a good value. I used 2 stroke for a cople of fill-ups and the stuff that Wal-Mart sells in the blue bottle is purty good stuff.

Oh, one other thing, I think the ratio is supposed to be 1/2 ounce of 2-stroke per gallon of diesel.

[Kennedy]

I think that a high quality fuel treatment is of much greater benefit as it can help remove water, improve cetane and combustion, clean the system and last but not least lubricate.

It has also been said that the lubricity additives that are commonly used have the ability to "attract" to the metals that they are designed to protect.

Nothing wrong with a good 2 stroke oil, just better alternatives.

[More Power]

2-cycle oil has been used with some success as a diesel fuel lubricity additive. After all, this type of oil was engineered to provide lubrication in dilute concentrations and to burn during the combustion process. In an older non exhaust-catalyst equipped diesel pickup, 2-cycle oil might contribute to fuel lubricity without much of a downside, but there are better choices, like what John mentioned. No matter what, don’t use 2-cycle oil in a 2007 emissions certified and Diesel Particulate Filter (DPF) equipped diesel engine.

Exhaust catalysts, like that used in your LLY, could experience more accumulation of unburned solids. Over the long-term, it could contribute to cat plugging. But, it's hard to know to what effect or how long it might take. Just a theory.

Jim