[Nadir Point]

Take this with however many grains of salt you like, but here's my anecdotal rendition of the case for diesel fuel lube. It is based solely on AUDITORY data. I also own a couple of Dodge Diesel pickups - a 91.5 and an 07 with the Cummins 5.9. The 91.5 is a rotary VE and the '07 is commonrail with the same or very similar CP3 injection pump found on the 335D. These things are naturally noisy, engine clatter galore everywhere all the time. It's normal. The rule of thumb on strange noise diag is just keep driving it. If something breaks, fix it. If you think you hear something awry, just keep driving it and wait to see what happens. I decided to try the stuff one day about 12 years ago after hearing about some issues surrounding ULSD. I added it with the engine running after a tip from a guy on a truck forum. As I stood there screwing the fuel cap back on to the 91.5 I was astonished to HEAR the injectors go down about 10dB noise level. The whole engine literally seemed to just quiet down as soon as it was circulating within a minute after adding the stuff to the fuel tank. That's all I ever needed to know about it.