Originally Posted By: Donald
You should go on the forums for your engine to see if the injector pump is mechanic or electronic and needs the lubrication that was in the old diesel, that may or may not be in the ULSD. The test I have done some reading on is the HFRR.
As a result I use 1 oz to 1 gallon of Walmart TC3 2 cycle oil. The VP44 in my engine really needs the lubrication.
MMO actually made things worse not better for the HFRR test. So forget using it.
If your injector pump is not over picky about lubrication, then I would choose a diesel additive once and awhile, but something made to be a diesel additive. I only use TC3 oil as its costly to add an additive to every tank.
Google the HFRR test.
That HFRR test was very well done!
I basically agree with Donald's recommendations but I don't think an additive is necessary very often. The lubricity issue is overstated based on my research. There are incidents of the new lubricity additives not being added to ULSD but they are few and far between and most diesel engines can deal with one tank of bad fuel. Anyway, I balance the risk against the cost and don't add anything on a regular basis to my road truck. In my farm tank, I add the 2-stroke oil because it's pretty cheap to do and easy since I add it when I add fuel. Once in a while, I toss some in the old pickup. Given it's reputation for being vulnerable, if I had a VP44 I might be as concerned as Donald. My DB2 pump isn't that sensitive and at 2k miles per year, nothing is going bad very quickly anyway.
For the most part, the common rail diesels are pretty numb on the lubricity issue. Mechanically injected engines are more sensitive to varying degrees. I think the Power Stroke HUEI engines are pretty numb also but there is debate over that and, not owning one, I haven't studied the issue enough to make a judgment.
Anyway, the risks are higher with certain engines and if the risk justifies the expense of regularly adding something, the 2-stroke oil is an effective and cost effective... as you will see in the test.