It seems impossible that a gallon of gasoline, which weighs about 6.3 pounds, could produce 20 pounds of carbon dioxide (CO2) when burned. However, most of the weight of the CO2 doesn't come from the gasoline itself, but the oxygen in the air.
https://www.fueleconomy.gov/feg/contentIncludes/co2_inc.htm
Pressure is the force per unit area acting on a substance. This force imparts energy to the substance and does work either by moving the surface of the substance inwards (reducing its volume) or if the force can't overcome the internal repulsion forces between the atoms, by causing the individual molecules to vibrate more. This vibration of molecules is directly related to the temperature of the substane so heat energy has been created.
http://www.funtrivia.com/askft/Question48599.html
Why you want to heat up my world?