For the power piston engine, the atmospheric pressure is used. Ie, as the piston moves in the race for admission, atmospheric pressure pushes the air mixed with gasoline into the cylinder to fill the space created. The speed reaches the gas to fill the cylinder depends absolutely on air pressure. If atmospheric pressure is greater, the force with which the gas is pushed into the cylinder will also be higher. Air pressure and atmosphere: The atmospheric air is composed of 78% Nitrogen, 21% lower concentrations of oxygen and carbon dioxide, argon, neon, helium, krypton, xenon, hydrogen, methane, nitrous oxide, ozone and water vapor. When atmospheric pressure is greater then

the number of oxygen molecules contained in a liter for example, is also greater. The highest concentration of oxygen per unit volume can burn more fuel at a time, which increases the engine volumetric efficiency, generate more power and develops more power.