Honda’s FCX Clarity FCEV is much more efficient than conventional gasoline-powered vehicles in converting chemical energy into power.
In gasoline-powered vehicles, fuel (gasoline) is used to heat and expand air, which then drives the engine’s pistons and crankshaft. Fuel cell vehicles, on the other hand, are much more efficient, because the conversion of fuel (hydrogen) to electricity, used to power the electric drive motor, is a more direct electrochemical process. Water is a by-product.
And since the FCX Clarity FCEV has significantly fewer components in the drive system, no pistons and no camshafts, the energy loss from these systems is eliminated.