[Dr. Scott W. Tinker] For nearly two years the gasoline in this can has been sitting in the corner my garage nearly forgotten, at temperatures as low as 20 degrees to as high as 110 degrees. But I could still pour to my gas tank in a few seconds and run nearly 100 miles. It's this remarkable density, versatility, and ease of use that make oil-based fuels so dominant in the market. In fact, 95% of transportation today runs on them, but there are competitors. The fuels making the most progress can run in the same kind of motor as gasoline, an internal combustion engine. The engine draws in fuel and air, explodes it in a chamber which pushes the piston down turns the crankshaft and makes the motor go. Gasoline, diesel, biofuels, compressed natural gas, and propane all can run in an internal combustion engine. Hybrid cars have one too, but there's is attached not just to the wheels but also to a generator which charges a battery much bigger than this one which runs an electric motor. Hybrid cars can run on electric motor, internal combustion engine, or both but all the energy comes from the fuel. Then there are electric cars, which have just a battery and an electric motor. But today, to get the same performance as an internal combustion engine requires a very big and expensive battery which takes hours not minutes to recharge, and the electricity to charge them comes from coal, natural gas, hydro, nuclear, and renewables. There's another kind of electric vehicle powered by a hydrogen fuel cell. Here, hydrogen flows into the fuel cell wants to combine with oxygen to form water. The hydrogen moves through a membrane and an electron is split off. The electrons flow as electricity through this wire to turn an electric motor. Some think the car of the future will be powered by a big hydrogen fuel cell rather than a big electric battery, but it's too early to know. Oil-based fuels running internal combustion engines have been with us for nearly a century and we'll see better and more efficient versions in the next several decades as alternatives continue to improve and compete for market share.