Originally Posted by Richbot
In theory. In practice the downside is probably reduced filtration of stank, they have carbon in them which has a limited useful life
but Rich is right, if you drive your car in a metro area like DC here, you will notice a difference in cabin air quality. I often find myself stuck behind stinky old cars, country-boy modified diesel trucks, and delivery trucks. I turn the vents to Auto recirculate and it detects the "stank" particles and immediately turns the outside vents off, and allows the filter to do the work.