2009 Dodge Durango Owner Manual - Page 284

282 UNDERSTANDING YOUR INSTRUMENT PANEL Regular cleaning of the inside of the windows with a non-filming cleaning solution (vinegar and water works very well) will help prevent contaminants (cigarette smoke, perfumes, etc.) from sticking to the windows. Contaminants increase the rate of window fogging. Summer Operation Air conditioned vehicles must be protected with a high quality antifreeze coolant during summer to provide proper corrosion protection and to raise the boiling point of the coolant for protection against overheating. A 50 % concentration is recommended. Winter Operation When operating the system during the winter months, make sure the air intake, located directly in front of the windshield, is free of ice, slush, snow, or other obstructions. This will also prevent snow ingestion into the ducts.