I've attached a .pdf version of the study results -
link.
It would be nice to have an updated set of test results, but I'm certain that these tests are not cheap to have performed by a certified lab.
Just to toss some additional data into the hopper for consideration (and probably to muddy the waters a bit), here's a nugget of data from the data sheet of the FPPF Lubricity plus Fuel Power product referenced in the original post.
This test appears to be the same one used by Spicer.
Comparison of results
HTML Code:
Tester Base Fuel HFRR Treated HFFR Net
Spicer * 636 675 39 worse
Research Institute 425 260 165 better
* actual lab not disclosed
Recommended standards
US - no greater than 520 microns
Engine Manufacturers Association - no greater than 460 microns
So the base fuel for the FPPF test exceeded the recommended standards to begin with.
The question that remains unanswered in all this is, Why would the results get worse in one case and better in the other?
Pending other data, the bottom line for me personally is to go back to 2-stroke oil but at a 200:1 ratio. As has been pointed out, experience shows little documented evidence of problems with the MB IP using ULSD, so for me the use of an additive is really just cheap insurance.
I've done a significant amount of research and there appears to be no updated data, and even data on current HFRR testing of current fuels is not readily available.