Welcome to brain Stuff from how stuff works dot com where smart Happens. Hi. I'm Marshall Brain with today's question why is it so hard to start some cars in the winter? The whole starting your car and cold weather thing could be a big problem for people who live up north, and especially for people who live in really cold places like Alaska. There are three reasons why cars are hard to start when it's cold. First reason is that gasoline, like any other liquid, evaporates less when it's cold.
You've seen this. If you pour water on a hot sidewalk, it will evaporate a lot faster than it will from a cooler place like a shady sidewalk. When it gets really cold, gasoline evaporates slowly, so it's harder to burn it. Sometimes you'll see people spray ether into their engines and cold weather to help start them. Ether evaporates better than gasoline and cold weather reason too. Oil gets a lot
thick or in cold weather. You probably know that cold pancakes, syrup or cold honey from the refrigerator is a lot thicker than hot syrup or honey. Oil does the same thing, So when you try to start a cold engine, the engine has to push around the cold, gooey oil, and that makes it harder for the engine to spin. In really cold places, people use synthetic motor oils because these oils stay liquid in cold temperatures. Reason three has to
do with batteries. Batteries have problems in cold weather because a battery is a can full of chemicals that produce electrons. The chemical reactions inside batteries take place more slowly when the battery is cold, so the battery produces fewer electrons. The starter motor therefore has less energy to work with when it tries to start the engine, and this causes the engine to crank slowly in cold weather. All three of these problems can make it impossible to start an
engine in really cold weather. People either keep their cars in heated garages or use block heaters to get around these problems. A block heater is a little electric heater that you plug into the wall to keep the engine warm. Do you have any ideas or suggestions for this podcast? If so, please send me an email at podcast at how stuff works dot com. For more on this and thousands of other topics, go to how stuff works dot com.