Outside air smells with HVAC off/recirc

[rsg123]

The weather in NorCal has been mild for the past month or so and I have been able to drive with the HVAC off. In my ICE car, driving with the HVAC off with recirculate mode on causes most outside smells (especially diesel smog) to be kept out. In my late 2014 85, many of these smells/smog enter the cabin quite easily with HVAC off. Is this normal?

 

[Gixx1300R]

When was the last time that you checked your cabin filter?

 

[rsg123]

It was changed during the 50k service which took place just before I bought it about 4 months/6k miles ago.
Does air travel through the cabin air filter when HVAC is off?

 

[Tdriver]

Try turning the system on and spray some freshener/deodorant thru the front air intake.

 

[murphyS90D]

If the car was completely sealed up you would use all of the oxygen in the cabin and suffocate. There has to be air flow through the car.

 

[rsg123]

If the car was completely sealed up you would use all of the oxygen in the cabin and suffocate. There has to be air flow through the car.

How does this circulation happen with the hvac off—through the cabin air filter and vents?

 

[rsg123]

Try turning the system on and spray some freshener/deodorant thru the front air intake.

That would take care of a musty-type smell that’s embedded in the system but where’s the diesel exhaust getting into the cabin with the hvac off?