Well after many tanks of plain diesel I added 16 oz 2 cycle to my tank and so far it has not dropped my mileage like it did the last time I tried it. But then it has not made any difference in the injector noise but I will give it some more time to work. If it does not improve my injector noise then I'll try PS and MMO again or if I have any more bad injector knock I can allways depend on Lucas to clean them up and quite the injectors down..