Air as Fuel

The substance your car burns the most of is air. Fuel is mixed with the air at ratios of around 14.6:1. For every gallon of gas you burn, you burn many, many cubic feet of air. The number of molecules of air entering the combustion chamber each time the intake valve opens will vary with the temperature of the air. Cold air is much more dense (the molecules are packed together) than warm air, so cars often perform better in cool weather. If more air gets into the chamber, more power is produced. For this reason, engines running at high altitudes or in especially hot climates have to be specially tuned to get enough air to run properly. If the air is compressed by a turbocharger or supercharger, more of it can be packed into the cylinders. The result is the production of greater power when this air is ignited.