This is for my local conditions -- YMMV. A couple of the underlined items are currently missing from kit. I promote keeping the vehicle in good repair which means keeping the fluids topped up rather than carrying extra fluids in the vehicle.
Car kit (store in trunk, glove compartment, centre console and door panels) - Depends on size of vehicle of what you can carry or your abilities.
Sunglasses
Garbage bags
Cell phone charger
Maps and/or GPSr
Toilet paper & alcohol hand sanitizer
Snow brush/scraper
Gloves, mitts, hat or toque, scarf or buff
Optional cold weather clothing (parka, insulated pants or bibs, socks, winter boots)
Emergency reflective sheet, tarp, (shelter) or poncho
Wool blankets or sleeping bag
Charcoal hand warmers
UCO Candle lantern, extra candles /w matches / ferrocerium rod / lighter
Flashlight, headlamp, batteries, whistle
Snap chemical lights
First aid kit
Personal emergency kit
Paper, pen/pencil
Ethanol or isopropanol NOT Methanol gas line antifreeze for fuel injected cars (also doubles as fuel for my alcohol stove)
Cordage, duct tape
Ranger bands (cut up inner tube used like a HD rubber band)
Bungee cords, brass or steel wire
Spare fuses,
hose clampsWD-40, silicone spray
Set of tools (wrenches, screwdrivers, pliers, side cutters, utility knife, battery post cleaner)
Collapsible road cone / Reflector triangle /
road flaresMechanical traction aid or cat litter/sand
Shovel
Roll of shop towels
Foot air pump or electric air compressor
Tow strap (need at least the weight of your vehicle = 1/3 of rated breaking strength)
Jumper cables (the heavier the better)
Lithium ion jump start battery pack
Water (keep in the cabin not the trunk, it will stay liquid longer except in the coldest climates)
Food (food not really necessary but it relieves the boredom)
Cooking container
Fire extinguisher
Gas can (empty)
Duffle bag, backpack or something else to carry your gear in
Hardhat, hi-vis vest, safety glasses, safety boots (I'm in construction so this is standard carry!)
Tire jack and wrench
Full size spare if you can fit it.
Keep your gas tank full; lowest grade fuel has 7-10% ethanol, which emulsifies and suspends water; is hydrophilic and can contain up to 4 teaspoons of water per gallon. Too much suspended water can actually lead to phase separation where the water-contaminated ethanol separates from the gasoline. Premium grade has zero ethanol so if you have issues with sputtering, engine stalling, missing or running rough – fill with premium grade for a tank.)
Don’t run your engine more than a couple of minutes to warm the vehicle cabin as the lower engine temperatures can lead to build up of gunk in the engine causing start-up problems. Judicial use of remote car starter.
In severe cold, do run your engine for at least 30 seconds so that the oil can circulate and lubricate the engine properly – especially turbo-charged engines. (The time it takes to scrape the windshield or brush off the snow is sufficient.) However, don’t run the engine at high speed until the vehicle has had a chance to warm up (about 10-15 min.) Turbo-charged engines should also be allowed to cool down for 30+ seconds to prevent “cooking” of the oil.
Your gas filler tube location on your car is indicated by the tiny triangle on your gas gauge.
Clean your battery terminals of corrosion in the winter by using a wire brush, solution of baking soda, coating the clean terminals with grease or WD-40.
Change automatic transmission oil, gear oils and brake fluids as per your vehicle manual.
Change and flush your radiator coolant. Have the garage test the fluid for the proper temperature rating and top up with fluid and distilled water. Note: if your coolant overflows or if you spill – clean it up right away because if your pets lick it up they can be poisoned from drinking the sweet tasting glycol fluid.
Use winter tires or studded winter tires because they are far more effective for control and braking than all-season tires. I use the minus1 system for my tires, i.e. I choose to use a wheel that is one size smaller but compensate by using a taller profile tire so that the diameter is the same. The taller tire is slightly skinnier and able to run through the snow better and they are generally cheaper than wide shorter profile tires.
Tire pressure gauge – check tires monthly for the correct and even pressure across all four tires. Also check your spare tire and inflate it to a higher pressure than your regular tires – you can always partially deflate a tire to the correct pressure.
Check the depth of your tire tread with a gauge or a coin. Less than 5/32” is not sufficient for travelling on snow while 4/32” is the minimum for summer tires on wet roads. A normal winter tire has between 11-13/32” depth. Slip a toonie in between your tread blocks. If the tread reaches the bear’s paws, your tires have lots of tread left (they are probably new!). If the silver part of the toonie is covered by the tread block, your tires are about half worn and if the tread reaches only as far as the letters (‘CANADA’ or ‘DOLLARS’) - your tires are worn and need to be replaced.
https://youtu.be/_xJxY04cZkkClear the snow (and mud and salt) off the vehicles including lights and roof.
Check weather and road conditions before setting out, let people know about your travel plans, use the work-alone travel app on your phone.
When in trouble: turn on your 4-way signals and raise the hood. People are far more likely to stop to help when you raise the hood.
Advanced signalling techniques (beyond honking the horn, blowing the whistle).
Ladies: if you are uncomfortable with the person who has stopped to give you help (might be a bit sketchy) then tell them that you have phoned for assistance already and are just waiting for them to show up. Carry bear spray for self-defence.