I've been adding 2 cycle oil to my VP-44 and my wife's 12V since 2001, 8 years now. Pulled the injectors once and they looked exactly as expected. No evil 2 cycle "gum" buildup.Now to the interesting part: I bought another used 3500 2001 with 117,000 miles. Shortly there afterwards, I started getting low power periods and P1693 (?), the code for "internal timing error". I didn't have the time or money to replace the VP at that time. So I experimented with heavy dosing of 2 cycle oil in the fuel. <100:1 mix ratio. I was able to drive the truck several more months before replacing the VP.My son didnt believe me about 2 cycle oil, his VP died at about 150,000 miles. Same code. He decided to try the heavy dosing of 2 cycle oil, and he was able to drive the truck for a month. But if he forgot to add the 100:1 2 cycle oil back wouold come the P1693 code. I had the same experience if I forgot to heavy dose.Is the heavy dosing a "fix"? Answer: no, the damage is already done, but the extra high dose of lubrication got the timing ring to move again.Suppositionally, I suggest that increasing the lurication quality of diesel fuel will prolong the life of the injection pump and injectors, since both are mechanical and I have not see a mechanical device that didnt benefit from improved lubrication.