A synthetic substance simmilar to gas could be produced and purchased.
If your willing to pay $50.00 a gallon a least....doesn't seem like such a good idea. In reality the future of transportation is in hydrogen fuel cells. Initially they will use a reformer to split hydrogen out of fossil fuels such as methane until a cheap effiecient method of creating and storing pure hydrogen is invented. Although a gassoline engine is about 20% efficient in harnessing the energy in gassoline a hydrogen cell using a reformer and methane is around 30% efficient.