Abstract: An automotive vehicle is described having on-board storage of free natural gas and natural gas combined with water to form a hydrate. The natural gas is preferably a mixture of methane and about 1% propane. It is provided with hollow metal plates. Cooling fluid can be circulated through the plates to form the hydrate and heating fluid can be circulated through the plates to decompose the hydrate. The pressure within the storage container is preferably between 450 and 850 psig. The free natural gas within the container can be used to start and warm the engine. The vehicle air conditioning system is used to cool the circulated fluid and the vehicle radiator and/or exhaust is used to heat the circulating fluid. The container is insulated with multiple layers of heat reflective material, e.g., aluminum foil, separated by glass fiber felt. Preferably, the layers are sealed and the space between the layers is maintained under a vacuum.