[agentorange]

Warm weather started kicking in recently, and I noticed that the HVAC flow was a little sluggish. When did I change my cabin filter last? I don't recall, but the car hasn't seen a lot of use since COVID, at least in mileage terms.

Got on to Rockauto and noticed that there is quite a selection of filter types. BMW usually recommends the charcoal loaded filters. However, a chart on the Rockauto site shows that the best flow is achieved with what they describe as "particulate" filters. See the chart in this link.

https://www.rockauto.com/en/moreinfo...LoMvOdH4PlEdfe

So, I rolled the dice and bought the Hengst E2991LI, the particulate filter for the F30. Wow, MAJOR increase in airflow for a given fan setting. I don't know what works for the rest of you when it comes to keeping cool, but moving lots of air with minimum fan noise is my preference. If you think the same, give this filter a whirl.

[wishbone]

I’m running hengst in both my f30 and f80 but maybe different ones??

https://www.turnermotorsport.com/p-5...sh-air-filter/

[agentorange]

That's a carbon filter. Takes out odors and pollution better than a standard filter at the cost of flow.

[wishbone]

Originally Posted by agentorange

That's a carbon filter. Takes out odors and pollution better than a standard filter at the cost of flow.

Ah, I think I knew that with the grayish image compared to yours

[Salty B.]

Almost all BMWs made since at least 2000 have "AUC" sensor that detects (hydrocarbon?) vapor and temporarily closes the fresh air intakes to the cabin if recirc is set to "A", so while that carbon filter might remove the first whiff of stank, it's not really necessary.

Even my old X5 has this function.