An electric car has a set of batteries that fuels an electric motor that can reach 15,000 rpm and 100 kW power for a powerful acceleration. Because of the high rpm of the motor, electric cars can have transmissions with only one gear ratio. The drawback is that electric cars usually go between 50 to 100 miles between charges. It can also be slow and inconvenient to recharge. Petrol-electric hybrid cars are an attempt to utilize the advantages of both of these car types, while mostly avoiding the disadvantages. Gas-electric hybrids use a gas tank, gas engine, electric motor, generator, batteries, and transmission (see fig.1). The electric motor can draw energy from the batteries, and also act as a generator to generate energy to store in the batteries. The Toyota Prius has a radically different transmission; other hybrids have conventional transmissions. Although most hybrid cars are petrol-electric hybrids, there is the possibility of producing hybrids from other technologies. For instance, petrol-hydrogen hybrids such as the Mazda Premacy Hydrogen RE Hybrid, which features a transverse hydrogen rotary engine (Haldis 2007). This hydrogen hybrid is the world’s first hydrogen-petrol dual-fuel system, and was being road tested in Japan in June 2008. The transverse mounting of the hydrogen engine, instead of the conventional longitudinal mounting, resulted in higher power output over a wide range of engine speeds (Mazda 2009). Hydrogen combustion energy is converted into electric energy.