Subject The car work better on a cold day? We note that the car in a warm day going well and unlike the speed increases if you move to a cool area. What is the reason? Fact that the instrument actually improves the car. A common mistake people where it is believed that the car is on the fuel. The fact that the car is working with a mixture of oxygen and fuel, air, and rarely more than the amount of fuel on one part to 14 part of the mix as a whole. The most important factor controlling the effectiveness of the performance of the car is "breathing." And works all parts of the car from the play button to the carburetor to the entrances of the valves, to secure this objective. It is known that cold air is heavier than hot air. When you enter the car in the cold, the number of atoms of oxygen entering the combustion chamber greatly increased. In addition, the water vapor in the cold air keeps the cooler mixture of burned and believes in a dense mass of gas to the combustion process. Thus, the energy resulting from the combustion will be greater, and thus will increase the effectiveness and power of the car. For this reason, we find that the results of an experiment when the car made always include a detailed explanation of the temperature and humidity in the air. This causes a difference in the performance of the car per the different regions and tends automakers to register their cars and test their results in the cold days.