a few years ago when it was actually economically feasible to produce bio diesel, the extra filters were a blessing. things got really quiet running b100.

 

It is a little quieter (which is a relative term for the 7.3L) under normal driving conditions, but it is most noticeable on the first start of the day. When I'm warming up the engine from a cold start I can tell it is quieter.

As for "difference," I do notice a noise difference (less of it), but with a stock engine pushing 213K I don't notice any seat-of-the-pants difference. I do know, however, that I am not sucking nearly as much air through the injectors which helps extend their life. One of these days I'll get Clay's FRx to finish off the driveway mechanic fix for the deadheaded fuel line issue.

I performed this mod when I first bought my truck nearly 5 years ago and have not had a problem with it (I harpooned the filler and vent lines when the tank was open too since it only takes 3 minutes to do while you're in there). I don't know how much it has contributed to the injector life, but I do have 213K on the OEM injectors and they are still going as strong and noisy as ever.