Editing Compressed-air car (section)

==Disadvantages==

[[Compressed air]] has a lower [[energy density]] than [[liquid nitrogen]] or [[hydrogen]].

While batteries somewhat maintain their voltage throughout their discharge and chemical fuel tanks provide the same power densities from the first to the last litre, the pressure of compressed air tanks falls as air is drawn off. There are mechanical methods (e.g. [[continuously variable transmission]]s or auxiliary motors) to reduce this effect, but they add expense.