The windshield wipers freeze up and fail to clear the windshield of ice and snow at almost anything under 32 degrees. I've owned many cars and trucks over the last 25 years and have never had such a terribly designed defrost/windshield washer/wiper system. At 20 degrees outside, I had the defrost on max continuously and still have to stop every so many miles to crack the ice off of the wipers and clear the windshield.