I don't know. I never use cleaners and my DIesels run fine. I've been thinking about trying some cleaners but haven't tryed them yet.

I would like to set up some of controlled experiment where results could be verified. But that is difficult for one person to do. Even if I had an assitant who would add the cleaners when I didn't know about it to eliminate the placebo effect.

Too bad we can't get Consumer Reports to do a controlled test.

P E H