Thread: Filters: OEM or Coopers

Been having a small think about this, since I've recently had a look at three fuel filters.

Seems to me that there are four parts to a fuel filter.

The metal bit that holds it all together - probably the most expensive bit to make.

The seal that stops the diesel from coming out the top - if it doesn't the filteris useless so it's going to work.

The drain-ey thing at the bottom - probably a good place to cut costs, does it snap off easily, does it have threads that will strip, does it have a hole at the bottom so you can drain rather than wear fuel.

The paper of the filter - the bit that actually does the work.

To my untrained eye, and I didn't crack the filters open, I just had a peek through the holes, all of the paper filters looked much of a muchness. Waffle paper, looked like there was an outer sandwich of paper with some kind of meat inside it.

The filters are all within x of being the same size, so there isn't likely to be more paper in there. I can imagine that there could be better paper in there, but fifty bucks worth?

Rick130, I'm sure you've cracked one open, is there any difference in the paper?











Ah, I've forgotten one bit, there's the painted logo on the outside.


That's got to be where the money is. My cheapies don't have any paint on them, paint costs a bomb.

Cheers
Simon

Well Simon, sad to admit that, yes, I have cut a few open... ops:
'twas a long time ago, and I compared the Fleetguard that came with my rig to a Crosland that I replaced it with.
They were both very well built, with, IIRC, the approx same amount of media.
Of course I have no idea what spec media they both had, and this is where cutting filters open falls down big time. The media is the most important aspect of the whole deal, and is the one part that looking at it and even measuring its thickness tells you bugger all. You have to rely on the manufacturers data, and this isn't generally published, although most will provide the info if you ask nicely.

Diesel fuel filters should generally have a higher specification media to an oil filter. The tolerances inside the pump are pretty tight. I seem to have a figure of under 7 micron rating for the media bouncing around inside my head at the moment, although that could also be the Chardonay consumed last night..... :wink:

IMHO, diesel fuel filter quality is more important than an oil filter. The clearances are tighter for starters.
FWIW I've been using a Donaldson (made in Germany) for the Bosch filter head on the Tdi. My supplier stocks these at a good price, otherwise I would have bought a head adapter and fitted a Delphi/Lucas/CAV HDF-296 (5.5 micron rating) equivalent cartridge, as used on a lot of trucks and farm machinery (including my Fiat tractor, which has two)

I've seen a number of tests where people have substituted empty cans for oil filters on engines, ran them for tens of thousand of km. Done oil changes and had the oil analyised, and the contaminent levels were the same as when the full flow filter was in place.
It appears that real filtration only happens with by-pass type filters such as the centrifugal one on the Td5, or the big dunny roll ones you used to see on some of the big trucks.
Of course the new syntheic medias being used such as Donaldsons' Synteq are sort of turning this theory on its head as they are able to filter down almost by-pass filter levels while having better flow and better capacity than their cellulose counterparts, albeit at more cost per unit. eg. a Purolator Premium Plus L30001 costs me around $3, wheras a Donaldson P169071 Synteq media version costs around $26-27. Both are Z9 Ryco equivalent.