Charcoal filters may be good in warm weather climates but not for cold. I discovered if the charcoal filter was cold, <10*F (<-12*C) and then you went into a car wash with humid air that the filter became wet, plugged it up then horrible fogged up the windows on the interior. This only ever happened with the charcoal filters. I submitted this review onto Amazon.
I believe the simple solution to that is to turn on recirculation mode before entering the car wash. I wouldn't want to breathe all those atomized chemicals in my truck!
If you're trying to keep your windows from fogging inside, you've got to keep your interior humidity down so there's no moisture to condense on the cold glass. Allowing warmer and very humid air into your vehicle is a sure way to fog the windows when you drive back into the cold, charcoal or not. The filter will absorb some of the moisture then have to dry out which means a time with that elevated interior humidity level and fogged windows. Since charcoal is a very absorbent material, I assume that it's retaining more of that moisture and therefore takes longer to dry, again adding more time of elevated humidity inside the vehicle.
On older vehicles you could run the A/C on a warm temperature to help keep the truck warm while removing the moisture. Because cold air holds less moisture it is more effective at clearing the condensate (fog) from the inside windows. Which is why most modern automatic climate controls blow cold air through the defroster. I'm not a fan of this because you end up with a repeating battle to clear the condensate. Blowing warm dry air on the glass works in two ways to clear condensate, carrying moist air away from the glass, and warming the glass to the point where condensate won't form. So if you're really having trouble with repeated fogging, hit the wiper warmers (raises glass temperature), and run the A/C with a warm temperature selected.
Unfortunately most automatic defrost modes also force recirculation mode off, enabling colder outside air inside the vehicle. When it's 15F or so there's not really any moisture in the air, so that's not a problem. When it's warmer, say 35F and rain/snow mix, you're going to have a big problem with condensation on the interior glass because of the amount of moisture entering the vehicle. You're actually better on days like that (and humid car washes) to leave the recirculation mode on, defrost off, but the A/C on with a warm temperature. Most auto HVAC closes off different baffles depending on the temperature setting. So selecting full cold, draws no warm air from the heater coil through the vents. Similarly full hot, doesn't draw any air through the a/c evaporator, which you need to help dry out the air in the vehicle. Warm air will draw from both, enabling a warm dry air for the vehicle. If you have the dual zone or automatic climate controls you're stuck, not much you can do aside from add the wiper warmers to increase the glass temperature. But the simple climate controls will allow for the combo of warm A/C air with recirculation on provided you're not in the defroster mode. You can select the split defrost/foot mode and then re-enable recirculation.
As for which filter is "the best," that's pretty subjective. Best can mean cheapest for many, best smelling, most effective at removing particulates, or removing fart smells.... best how!? Personally I use the Wix Charcoal Filters #24511.
