Originally Posted by simsurfer
First chance I have had to reply (busy yesterday). Tried the AC thing turning off the recirculate and so far it has worked like a charm :-) I think my error was the fact that I had the recieculate option turned on when running the AC, that and or I normally dont run with AC on, just the vent.
I will try though the Rain X thing though this weekend when Im at the store.
Thanks all.
Save yourself some money first and just clean your windows very well with some glass cleaner (Windex, etc.)
The reason why the windows fog up is that there is excess moisture inside the car. Mainly this is because there's one or more human beings in it, creating the moisture by breathing. Plus, the outside is cold, the inside is warm, so the barrier (body, glass, etc.) wants to condensate. This forms the moisture (fog) on the warm side (inside).
The air-conditioning system in your car is no different that in your house. You are passing warm, moist air over a cooling coil to cool the air, and this in turn, removes moisture. The puddle under the car in the summer time that you notice is moisture that has been removed from the interior air in your car.
By running the fresh air (Non-recirc), A/C button on, and the temp dial about 1/2 way, you will reduce the moisture the fastest, while still gaining some heat in the car.
Try not to run the heat "full blast" (the temp dial all the way to red), and you should see a marked improvement. You can try this without running the A/C. Crack a back window if no one is riding back there, allowing more fresh air in also.
IME, the side windows are the toughest to keep fog free, because you are closest to them, and there's not a good bit of air blowing on them. The front and back are easiest, due to the rear window defroster and the front has the air on it.
Hope this helps.