That's a really poorly written paper and it makes some totally unsupported claims. They show a typical 3 bar (43.5 PSI) gasoline port injector but then they test it at a very untypical 110 PSI. They use a very unconventional spray droplet measuring system that I have grave doubts about. I don't really see a significant difference between the two curves. The vast majority of the fuel will be contained in the large droplets where there is no separation. Only at the very low end is there any separation and that is too small a difference to have any significant effect on fuel economy.
The diesel injector is never shown but the test in that case is at a totally unrealistic 200 PSI. There is no diesel injection system that operates at such a low pressure, in fact the major improvements in diesel systems has come from a tremendous increase in injection pressure over the years. Again, there is no significant visible difference in the quantity of large droplets.
The claims on improved combustion efficiency are presented without any evidence to back them up. It would have been easy to make some dynomometer or highway tests with such a simple apparatus to verify the claims. I expect any improvements would be minuscule at best, certainly not the huge improvements claimed.
