Given the polar storm over the US at present, and temperatures hitting record lows, there's already reports of stranded motorists.

I've once been in a situation where we needed to keep our engine turning over every couple of hours to keep it running (-20C, 4400m), but what steps can you take when it's extremely cold (eg the -40C currently in Yakutsk, Russia or the -25-40C with windchill in the eastern states at present).

This is not about the mechanics of a car - eg altering fuel composition, but more how to deal with the sudden onset of extremely cold weather during a trip.

  • 2
    WW2 troops in Russian winter used blowtorches to thaw oil to allow starting. Allowing battery to fall below 0C is unwise. Trying to start below about 10C is unwise - capacity is much reduced. Some people install "block heaters" for intemperate climes. Jan 7 '14 at 4:42
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    Is this for close to inhabited areas, or just when you are on the road away from electricity? I think it makes a huge difference for the answer. I know that in these area day just upon arrival plug in the car to a socket (the car is not electric/hybrid), just to be able to start heating it when leaving.
    – Bernhard
    Jan 7 '14 at 6:57
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    It would be unusual to drive your own car into a much colder than usual area. Typically the cold comes to you, or you're in a rental car. The first scenario is offtopic for here and the second is unanswerable since you can't prep a rental car for cold, or add a garage to your friend's house to keep the car in. Jan 7 '14 at 13:55
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    @MarkMayo how about asking how to evaluate a rental car for extreme weather? (Most don't have snow tires or block heaters, and don't get me started on snow brushes and scrapers in rental cars) or how to prep your own car for driving from California to Winnipeg. Once you're in a cold place with an unprepared car about your only option is "park it indoors, and possibly leave it parked." Jan 7 '14 at 16:09
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    @KateGregory - you are incorrect, there are plenty of times when people drive from warm weather to cold weather, especially around this time of year as they visit relatives for the holidays. I know one family in particular who had relatives drive all the way from Arizona to spend 2-3 weeks with them in Maine for Christmas.
    – ZeekLTK
    Jan 8 '14 at 19:50


There are multiple factors involved with being able to drive in cold temperatures even with the onset of cold temperatures being fairly sudden 2-3 days notice.

You should be looking at the following major components: Engine, Cabin, and Tires and looking at them separately and then there are additional subsystems and conditions that will make for an interesting conversation on its own so let's begin:


There are 2 important aspects in making sure that your cabin can provide you a comfortable ride:

  1. Weather stripping - There are kits that are being sold in auto stores and online that will provide better seals for your cabin during winter. Cold temperatures especially on the spectrum on -25 to -40 C tend to make rubber harder and more brittle and thus when you open the doors and closing them you can break those down and make holes in insulation making it more difficult for you to drive when you have to put on thick gloves and hat and shearling or similar to make sure you stay comfortable(sorta).
  2. Heater - Make sure it works! Cars like older Zaporozhets had to have separate heaters because of the rear mounted engine and that heater (as it turned out) was basically a pilot light fed by gasoline from the tank heating the air that was pushed into the cabin. If this thing went out... Well you get the idea.
  3. Windows - In addition to making sure that mounting weather stripping is up to par you will have to look whether or not your glass especially on the Windshield is good. I have personally had issues in one of the cars I owned when I had to defog the the windshield it cracked because of the temperature difference between inside and outside. Thankfully it was only a crack running along the bottom so I could still drive but a spiderweb on your windshield could pose a problem. This is usually not a problem for the newer cars with Tempered Glass installed by the manufacturers but it could be a concern for older ones and for cars that had to have any of the glass replaced, which could be done by the outside parties.


There are several subsystems that will need to be looked at for it to function properly so let's try:


The battery is important not just to start the car but also to make sure that your electrical systems run. A shorted out battery will stop your electrical systems from running. In addition to that the colder temperatures slow down the chemical reaction in the battery thus robbing it from power needed to start your car, so if the battery is 3 years or less and your car will only stay in the cold not for an extended period you can safely leave it in the car and you should be OK to start the car after. If not I would suggest removing it and keeping it indoors and reinstalling before you need to use it. Granted of course that you can remove it, some times it's not that easy especially with modern cars that only have electronic keys. So if you have a batter that is 3+ years old it might be a good idea to replace it.

Engine Block and Motor Oil

Motor Oil needs to stay liquid and be able to be pumped into the engine when it starts so Winter viscosity needs to be appropriate. For the longest time in the US it was fairly standard to have cars with 10W-30 grade motor oil and mechanics looked at you funny when you requested 5W or even 0W oil which performs better at lower temperatures and helps to prevent your engine from seizing because oil pump can't put the what became of motor oil at those temperatures into the engine to lubricate the moving parts.

Engine Block also helps to be heated up using Electric Engine Block Heaters when the car is parked since it provides heat to the block keeping fuel, oil, and coolant at temperatures above freezing so that engine can start better. This usually comes as standard or optional equipement on trucks with large diesel engines to keep the fuel from gelling but that's next.

Fuel and Fuel System

There are different precautions that may need to be taken for gasoline vs. diesel fuel. Diesel Fuel because of generally higher viscosity or presence of bio components at lower temperatures tend to gel so there is usually a heater for the fuel tank and fuel lines that is built in to the car. Whether or not it is hooked up to the Engine Block Heater that may come with the car remains to be seen but usually is. Some diesel engines provide Glowplugs to heat up the block somewhat to help with the start.

Gasoline engines for the most part don't have the problems with gelling fuels and freezing which happens around -50C, however, modern gasolines have additives like Ethanol which freeze at higher temperatures, as well as potentially water that may have been mixed in with the gasoline, that actually can clog the fuel pump and fuel line (I know of several manufacturer's recalls, most notably Nissan Altima recently)

Cooling System

The antifreeze in the cooling system depending on the temperature can contain water and freeze in the pipes or radiator or in the water pump (just watched my friend's Porsche blow an engine due to this). So if you have water instead of antifreeze in the system things might get even worse.

If you do happen to have it frozen you will need to either tow the car/truck to the garage to have it thawed or if you are not particularly afraid to use it I have seen Blow Lamp used under the engine and fuel tank to thaw the engine block and fuel lines on the truck sufficiently to get it started.

And Last by not Least:


When it comes to tires you have to take into consideration the fact that you may have snow and more concerning ice on the road. Tires while seem to be an after thought are important. When temperatures drop summer tires which are naturally harder tend to slip and provide worse traction then all season or winter tires and while the primary purpose of the winter tires is to provide better traction on Snow and Ice one can't overestimate their use if the cold spell persist.

And the very last suggestion: if you're renting a car then you might just call the rental company to help you out of a jam, but for the rest of us having an Auto club membership might just come in handy.

So to make a long story short: If you try to bring your desert tuned car to drive on the Dalton, or Dempster you might not fair so well.

  • 5
    Now that's an answer!
    – Mark Mayo
    Jan 8 '14 at 22:14

TL;DR Cold will kill you. There are things you can obtain in the cold place, and simple things you can do while driving, that might save your life.

Driving in the cold can be dangerous to the point of being deadly. I've been driving in Ontario (and living in the countryside) for over 35 years. I've been in the ditch countless times (usually some guys in a pickup truck come by and get me out, sometimes it's a tow truck thing), I've been delayed hours by road closures, I've cancelled plans because they say not to drive, I've slid and spun on all kinds of ice (fresh wet ice from freezing rain, old frozen stuff with soft white snow on top, black ice, and more) including sliding into things I didn't want to slide into, and faced hills that no-one could get up - you just have to turn around and go a different way. Wandering into a situation that scares locals is generally not going to be smart. However, if you find yourself in it, at least make the best of it.

You will need:

  • knowledge of a local radio station to listen to for traffic and news. If the local news starts saying that the police are saying to stay off the roads, stay off the roads
  • snow tires. Not "all season tires", snow tires. If you are driving only within a city and it is further than 10C or 20F below freezing then perhaps you are ok without snow tires. (A very cold dry road is safer than a slippery icy or snowy one.) Otherwise your "stay off the roads" filter will need to kick in sooner than everyone else's.
  • warm clothes: hats, boots, mitts, serious coat etc. You don't have to wear them while you drive (your car surely has a heater) but you need them with you in case the car gets into trouble. Some people also bring a candle in a coffee can (and matches) and an extra blanket or two, but I've never needed these.
  • snow scraper and brush, and some idea of how to use them. Rental cars are generally missing these (as will your car be if you drove from somewhere warm) but they are super cheap ($3, $5) so get someone to tell you where you can buy some and take a short detour to get them. (Get an extra bottle of windshield antifreeze while you're at it, in case you run out on the road, and by the way that place will probably sell you some ugly hats and gloves too.) Not being able to see out the windshield will kill you. Wear your gloves when clearing off the car and clear the outside mirrors, headlights, hood and roof as well as the glass. In a pinch a credit card can function as a scraper.
  • food (a granola bar, say) and drink (a bottle of water) in case your one-hour trip turns into 6 or 7
  • a working cell phone and a way to charge it
  • knowledge of where you are so that if you call for help you can tell people where to find you. A map or a mapping app so you can work out detours if you can't just follow the crowd.
  • a way to find gas stations, coffee shops etc, again for dealing with extended trips (last week a 2.5 hour trip took me 5 hours, using more gas, windshield fluid etc than I planned, and meaning we needed a bathroom-and-coffee stop along the way.) Install an app or do some searches before you leave. Learn to read the "what is at this exit" signs along the highway system you'll be using.
  • understanding of the features of your car that you never use, or features in this car that your car does not have such as fog lights (also good in blowing snow), rear window defroster, the various "defrost, feet, faces" settings of the heater, etc. Learn how to fill the windshield antifreeze in the daylight in case you later need to do it in the dark.

About starting

If the car has a block heater, plug it in, even if that means parking somewhere less convenient. (The cord is very short: ask someone for an outdoor extension cord unless you're in Northern Ontario or Winnipeg where there are handy plugs at the parking spots.) When it's time to go, start the car, then get it all cleared off of snow and ice. This will get the oil and the engine happier and also get the inside a little warmer.

If you had a very hard time starting the car you may not want to turn it off for a short stop such as coffee and bathroom. If so, go in shifts so that one person stays with the running car. Cars are stolen in super cold weather because people leave them running and go inside. Note, you cannot leave the car running while getting gas.

Be gentle to your battery. Do not leave the key at "on" if the engine is not running: this will blow the heater fan, run the defroster wires in the rear window etc and drain the battery. And you need every speck of juice it has to start the car with thick sludgy oil. Use "acc" to hear the radio with the car off, or just leave it off. Also try to not use the dome light or headlights if the car is not running.

On the road

If it's very cold (say -25C) you may find the windows are icing up no matter what you do, and you may have to divert all the heating to defrost and none for your feet, or turn the fan up so loud that it is super uncomfortable. If it's freezing rain, you may find nothing will keep the outside windshield clear and you'll have to pull over and scrape. These are uncomfortable and inconvenient things but they are far better than waiting at the side of the road for police or ambulance after your accident.

Do not let the gas tank go below half full. You may need more fuel than you planned to go the distance, or if the crappy weather includes power failures you may not be able to get gas where you thought you could. Fill up more often for safety's sake. When getting gas, check the headlights and other lights - they may be coated with ice either if you're driving in freezing rain, or just because of mess splashed up from the cars in front of you. This can seriously reduce the light that gets out.

If it is slippery, slow down. Leave more space between you and the car ahead. Brake slowly - partly so you don't skid and partly so the car behind you has time to react.

Most important

Above all, don't be afraid to give up and just stay somewhere warm and safe, and head out again when the weather is better. Living somewhere very cold you understand that human wishes sometimes have to just wait until nature feels like letting it happen. Being prepared is safer than being unprepared, but sometimes the only safe thing to do is stay off the roads.

  • 1
    You should add a TL;DR section. They actually work to get people to read through longer anwers. Also stuff like section headings. Especially after we read through one long answer and then get to another long answer. I say this because I notice your answer doesn't have many upvotes yet and I'm not going to vote until I read it all ... Jan 9 '14 at 5:50
  • @hippietrail I generally hate these but, ok. Jan 9 '14 at 13:17
  • Really? It's a great answer but was a bit of a wall of text compared to the other one. I couldn't think of any other reason yours had less votes. Jan 9 '14 at 15:56
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    @hippietrail I spend a lot of time on the workplace where it seems like half the answers are written with headings, executive summaries etc and I don't like the style or the feel of it at all. It's done even for relatively short answers. I decided my prejudice against that was keeping me from organizing this long answer properly, so I did it. I still in general dislike it for medium length answers. Jan 9 '14 at 15:59
  • 1
    Yes I only like it for long answers too. Jan 9 '14 at 16:02

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