[indigo6]

Hi all,

I see that there are two filters for the G30. An activated charcoal filter and a particulate filter. The parts advisor said the particulate filter is just a paper filter, but for some reason it’s more than the charcoal filter.

https://parts.bmwofsouthatlanta.com/...116996208.html

https://parts.bmwofsouthatlanta.com/...116996209.html

I doubt there is enough carbon in the charcoal filter to actually make a difference. I’m seeing references to the China version of the car for the particulate filter and I’m wondering if it might have better PM2.5 filtering ability due to pollution in some Chinese cities.

Thoughts?

[bpbaud]

Originally Posted by indigo6

I doubt there is enough carbon in the charcoal filter to actually make a difference.

Why?

[indigo6]

Originally Posted by bpbaud

Why?

Most effective carbon filters for reducing VOC’s in the home have 15+ lbs of active carbon. These filters work by adsorption, with too little carbon, the filter is quickly overwhelmed and becomes ineffective as all the carbon is used.

[bpbaud]

I think that's why BMW recommends replacing it regularly.

[indigo6]

Originally Posted by bpbaud

I think that's why BMW recommends replacing it regularly.

By quickly I mean far less time than the recommended interval.

[timmahh]

This diagram seems to show two particulate filters in a set. Perhaps in some places the factory offering is carbon activated, while in other's it's just a particulate filter. (Or the diagram is just showing that either part number is "part no.1" and fits there.)

http://www.realoem.com/bmw/enUS/show...diagId=64_2439

I noticed the L8AAA=No/Yes for China as well, however in either scenario both are listed as options:

http://www.realoem.com/bmw/enUS/show...diagId=64_2439