BMW does not manufacture their parts nor fluids.
That is relabeled Liqui Moly diesel additive -
https://www.amazon.com/Liqui-Moly-20.../dp/B002PE95ZA
When my wife had her TDI, I did notice a quieter, smoother running engine, and about 1-2mpg average more per tank, when I used Opti Lube XPD formula (all season) when we lived in the North
I just ordered about 6 tanks worth of XPD, and the nice people at Opti Lube are sending me some samples, of their Summer+Cetane (2 tanks worth of doses) - XL Lubricant formula (2 tanks worth), and Boost (2 tanks worth)
I am going to run the following tests and share my results but be advised it may take a while, we only drive about 350 miles per month on average LOL (both of us work from home)
Will reset trip and calculations each tank when I fill up, I am going to try out:
-Summer+ with XL (50/50 dose)
-XL with Boost
-XPD only
I don't get much more than freezing temps so I am not *as* concerned about anti-gel here in the South, but I do believe that we still get winter diesel blend, which I'll have to confirm. XL and Summer+ do have some water dispersents and deposit additives (Summer has more deposit additives, while XL has more water demulsifier) - XPD has more water demulsifier than XL, and the same deposit additive as Summer, PLUS it has anti-gel -
XPD is by far the most to use per tank, along with their Winter formula (for you extreme northerners with cold temps-
I can't imagine I would **need** XPD in the winter, considering the vehicle is garage kept and if we get more than a week of temps below freezing, it's a statewide travesty. Hoping the XL/Summer+ will be my ticket.
The HFRR rating on the XL formula and the XPD is astounding, and that is the number I am most concerned about - lubricity for the fuel pump - bottom chart on their website -
http://opti-lube.com/