Something I learned, after almost two million miles of commercial driving throughout the North Country, Canada and the West…including Washington, DC, where I really discovered this…is the following:
If your windshield is building up with snow, at a rate that prevents your windshield wipers from keeping the snow, or ice cleared, the best way to heat the windshield is to turn the Sun Visors down with the heater setting defroster mode control on full blast and the fan setting on its highest setting.
Turning the Sun Visor down, captures the Heat against the Windshield, making the heat more effective in melting the snow, or ice.
If your vehicle has an option for “Inside Air” or “Recirculate”, use that setting as well with the highest heat setting and fan setting.
If your vehicle has “Automatic Temperature Control”, set the temperature to the highest setting, and use the manual override to keep the fan mode on the highest setting.
Your vehicle will get extremely warm in this process (depending on outside temperatures), however, if you lower the Rear windows, on both sides, NOT more then 1/4-1/2 inch you’ll be able to force the hot air outside, and sometimes increase air flow to the windshield.
When this is all happening to you, NEVER, EVER STOP IN THE MIDDLE OF THE HIGHWAY…You will be injured, or killed…as well as others, because no one else can see, either.
If you have to go slow, ALWAYS use your 4-way flashers.
I hope this helps keep you safe… “God’s Speed”
Or maybe better yet, do as I have done more than once, pull in to the next safe area and wait for better/safer conditions.The only issue I have about that advice is about the “recirculate” setting. I’ve read in owner’s manuals that you should only recirculate the air with the air conditioning on. You don’t want humidity to build up on the inside of your windows, so if you can run both the a/c and the heat at the same time, and get hot air that is just as hot as if you weren’t running the a/c, then run the a/c AND the heat.
Commercial truckers often have to cover part of all of their radiators in the winter in order to get the heater to work right. Cars don’t usually have this issue, so I don’t think four-wheelers have to worry about this as much as truckers. Even without recirculating the air and lowering the sun visors, four-wheelers can usually get all the heat they can stand.
As a northerner, I like to pride myself of “gettin 'er done” in adverse conditions, but occasionally, commom sense says, “just park it already.”
Happened to me when headed south to get underneath a wicked winter storm. Parked it SE of StL when I started getting freezing rain: no “incident”; I just noticed that “cars in ditch” exceeded “cars on road” by a 2:1 margin.
So, ice is one “no-go” for me; “loose snow higher than ground clearance” is another. Doesn’t matter how good you are if your wheels aren’t touching.
" You don’t want humidity to build up on the inside of your windows, so if you can run both the a/c and the heat at the same time, and get hot air that is just as hot as if you weren’t running the a/c, then run the a/c AND the heat. "
All, Many, Most Cars Automatically Run Air Conditioning With The Heat On When They Are In Defroster Mode, Which Is The Mode Selected In The Original Post By Snowshoe.
CSA
Using the sun visors in that way seems like a good piece of advice. Will definitely look for an opportunity to try it out. It took me MANY years to convince another driver in the family to use the AC when it was cold outside, while setting temp to warm to keep windshield clear so it may take a while to convince same to use sun visors when the sun isn’t shinning. But, it took her years to convince me to do a lot of things the right way too.
I’ve been using the sun visor down advice for years. My 90 Pathfinder had very poor defrost. Only way I could clear the top of my windshield during below 0 weather was to put the visor half way down.
I heard that most cars automatically turn on the AC when in defrost too…but I’ve NEVER owned a vehicle that does.