[mountainmac]

Does anyone know the micron size of the fuel filter on a 2015 328D? I looked all over and could not find it. The reason I am asking is I had a Dodge Cummins diesel and Cummins stated to use a 2 micron fuel filter. This due to the USA fuel being of lower quality and having the potential of damaging the common rail fuel system. Since I could not locate a drop in 2 micron for the Cummins, I ended up going with a 2 micron spin on filter after the drop in 10 micron. So I want to make sure the N47 also is protected.

Thank you very much for your assistance.

[328iX]

Probably impossible to find, for the aftermarket, Mahle/Mann don't post micron ratings or efficiency and rather just claim "long life". You won't find anything on their websites other than Mahle claiming "dirt collection
efficiency of 3 to 5 μm" regarding their multi-layer filter medias.

Chances are one of BMW's filters are made by them so..

[mountainmac]

Hmmmm....well then I just may work on adding a 2 micron spin on fuel filter.
Thanks Dave

[floydarogers]

In the 10 years I've had my 335d and been monitoring the forums on diesels, I don't recall *any* engine failures due to bad fuel (I've seen several that failed due to miss-fueling.)

I think you're chasing a will-o-the-wisp, and borrowing trouble.

[mountainmac]

I am saying that fuel quality has not kept up with the newer diesels as they have had to meet stricter government regulations while increasing power, fuel economy and longevity. It is obvious that if a diesel is made much more precise and with closer tolerances, then the fuel to run it must also become better for the diesel to run at its peak efficiency. Since diesel fuel is also a lubricant, the days of diesel fuel is just diesel fuel are long past and, with the advent of ULSD (lower lubricity and a cetane rating between 40-45), the HPCR is even more prone to premature failure.

Cummins and CAT both recommend 2 micron filters and the links I posted below also recommend 2 micron. I used a 2 filter system in my Dodge diesel and never had any issues. So, I think I will continue working on the addition of a 2 micron filter to my diesel.

And to Floyd let us say that we can agree to disagree

I have listed some websites that have valuable information as to why I see the need for a 2 filtration system.

https://www.cumminsfiltration.com/si...compressed.pdf
https://www.fuelsinstitute.org/getat...-Injectors.pdf
http://www.mycleandiesel.com/pages/H...elEngines.aspx
http://www.sacea.org.za/docs/SAIT%20...s_2_Shrunk.pdf
https://www.the-triton.com/2016/01/s...k-for-filters/
http://citeseerx.ist.psu.edu/viewdoc...=rep1&type=pdf

[328iX]

Originally Posted by mountainmac

I am saying that fuel quality has not kept up with the newer diesels as they have had to meet stricter government regulations while increasing power, fuel economy and longevity. It is obvious that if a diesel is made much more precise and with closer tolerances, then the fuel to run it must also become better for the diesel to run at its peak efficiency. Since diesel fuel is also a lubricant, the days of diesel fuel is just diesel fuel are long past and, with the advent of ULSD (lower lubricity and a cetane rating between 40-45), the HPCR is even more prone to premature failure.

Cummins and CAT both recommend 2 micron filters and the links I posted below also recommend 2 micron. I used a 2 filter system in my Dodge diesel and never had any issues. So, I think I will continue working on the addition of a 2 micron filter to my diesel.

And to Floyd let us say that we can agree to disagree

I have listed some websites that have valuable information as to why I see the need for a 2 filtration system.

https://www.cumminsfiltration.com/si...compressed.pdf
https://www.fuelsinstitute.org/getat...-Injectors.pdf
http://www.mycleandiesel.com/pages/H...elEngines.aspx
http://www.sacea.org.za/docs/SAIT%20...s_2_Shrunk.pdf
https://www.the-triton.com/2016/01/s...k-for-filters/
http://citeseerx.ist.psu.edu/viewdoc...=rep1&type=pdf

I'll be interested to know what you come up with

[n00bkiller944]

I wouldn't mind having additional filtration for piece of mind. Especially if it is not super intrusive to install.

[mountainmac]

I finally heard back from Mahle:
Thank you for your interest in MAHLE fuel filters.
KL 736/1D initial efficiency is 91% at 4 micron.

Kind regards,
Lisa Levra
MAHLE Aftermarket Inc.
Product Management (MND)

I am not pleased that 9% of contaminants are getting into my system so I am going to go with a 2 stage filter setup as recommended by diesel engine makers.

Right now I am seriously considering this one;

https://www.glacierdieselpower.com/i...f=category:111

[328iX]

Originally Posted by mountainmac

I finally heard back from Mahle:
Thank you for your interest in MAHLE fuel filters.
KL 736/1D initial efficiency is 91% at 4 micron.

Kind regards,
Lisa Levra
MAHLE Aftermarket Inc.
Product Management (MND)

I am not pleased that 9% of contaminants are getting into my system so I am going to go with a 2 stage filter setup as recommended by diesel engine makers.

Right now I am seriously considering this one;

https://www.glacierdieselpower.com/i...f=category:111

ahh yeah that's pretty bad, but considering it has to also filter water out i'm not sure what's acceptable or not in a primary and single filter.

Curious to see how and where you mount that

[rbreding]

There was an aftermarket 2 micron add on for the VW common rail to protect the cp4 pumps IIRC. Although specific to the VW this might give you some ideas.

[mountainmac]

Thank you I will look into the filter.
I wonder what would happen to the recently released extended warranty for the fuel pump with the addition of a 2 micron filter.

[mountainmac]

Hey, what is the size of the fuel line at the fuel filter and does it change in size when it gets to the engine compartment? I looked everywhere and could not find it.

Thank you very much for your assistance

There was a guy making those aftermarket 2 micron systems for the VW TDI on their forum but I do not think he is making them anymore. If I could get the size of the fuel lines, I think Richard at Glacial Diesel Power may be able to put something together.