Pour it into your tank just before fueling. Use isopropyl, not methanol. This is the main ingredient. They can blow out when you close them. The main reason is that batteries have to work so much harder in cold weather.
Engine oil is thick, so engine cranking effort is much higher.
Also, a battery's efficiency decreases in cold temperatures. A simple load test and cleaning of the terminals will prevent a no-starter. Be sure to have had your battery checked before the wintery weather hits to be sure it has enough starting power for those cold New England mornings. We are equipped to do this for you. There are many sensors in your car.