Saab engineers figured out how important fresh air was to keep driver alert.
Fan control will not shut off fan - i.e. always fresh air pushed into the cabin. 1-2-3 speeds.
To shut off air/fan you must use the distribution switch (defrost, side vents, floor vents ...) and put at 0.
Do all cars do this now days? Seems so obvious. I think Saab 99 thru 900 (1967-2000 approx.) Maybe from the beginning 1950s?
Cabin Air Filter standard developmenthttp://fiatec.com/fileadmin/user_upload/downloads/PAPER2000.pdf
I guess nobody 'rolled coal' in sweden back then.
I hope not.
Fumes coming from the truck in front of you may not be that "fresh".
I hate it when people think they are smart and try to think for others.
For example our old Prius disabled control over navigation if the vehicle moved, even with someone in the passenger seat...
Dumbest thing ever, and frustrated me endlessly
I hate having air blown on me - except when I'm riding my motorcycle or driving a convertible. If they can ventilate the cabin without me feeling it, I'm good. But I agree there are times when I want to completely shut down ventilation as DTsea points out.
So. the Saab is perfect - you can shut it down AND vents allow you to push air up down or side ways.
Or did I confuse you about fan vs distribution controls?
And don't all vents allow you to direct flow?
I ask, as I have only owned 2 cars, Saab 99 and current 900 (did get to use Moms '64 Corvair).
Sorry I'm lazy and didn't want to go car looking and thought I'd get some useful info.
Small wonder GM shut down Saab?
"Fumes coming from the truck in front of you may not be that "fresh"."
"I hate it when people think they are smart and try to think for others.
For example our old Prius disabled control over navigation if the vehicle moved, even with someone in the passenger seat..."
I had to drive my new Prius for 4 hours on the freeway yesterday with the open hatch warning noise going non-stop. Had a load of Unistrut sticking out the back.