With everyone in a frenzy over fuel prices, all kinds of crazy devices are now flooding the market and promising to slash your gas bill by improving your mileage.  The most common claim is that for a couple hundred bucks, you can convert your existing car to burn a combination of water and gas, doubling your gas mileage! 

But are these things for real, or are they just a scam by a clever snake oil salesman?  Being a naturally skeptical person, I set out to find the truth – can you really run your car on water?   

When in doubt, I tend to turn to the laws of physics (and people who actually understand them).  These so called “hydrogen fuel cells” are actually nothing more than a simple electrolysis device that uses electricity to split water into its constituent components — two atoms of hydrogen and one of oxygen.   The gases generated by the electrolysis of water can be recombined by way of combustion to release energy.  This is not new technology – electrolysis has been around for decades. 

Sounds pretty good, huh?  Unfortunately, the first law of thermodynamics states unequivocally that the energy generated by recombining the hydrogen and oxygen through combustion can only ever be equal to the amount of energy it took to separate them.
Even worse, there are multiple energy losses involved in the generation of the electricity, the delivery of it to the electrolysis cell and then the combustion process.  We actually recover far less energy from burning the hydrogen than it took to create it!  Therefore, these magic “water-for-gas” devices actually cause your car to burn MORE fuel in order to heat the water in the electrolysis cell. 

Besides, don’t you think that if cars could easily run on water and gas that the auto manufacturers wouldn’t have jumped on it by now as a means of selling those slow-moving, large SUVs?  Just remember that old adage about things that sound too good to be true…

 (Special thanks to Bruce Simpson of the Aardvark Daily for explaining the physics.)

Frenchman Etienne Lenior patented the first gasoline engine in 1860 and drove a gasoline powered car from Paris to Joinville just two years later.  Over the next 150 years, gasoline became the fuel of choice for the personal automobile due to its abundant supply, cheap price and high-energy content.  I’m sure that early automakers like Gottllieb Diamler, Karl Benz and Henry Ford never anticipated that this technology would lead to a 400 million gallon per day habit in the United States.  Our own fossil fuel addiction, plus new demand from increasingly industrial countries like India and China, has led to record high gas prices, global warming, and an indirect funding of terrorism.  Ideas like environmental conservation and energy independence are no longer limited to “tree-hugging hippies”, but are now discussed frequently by mainstream America under the badge of patriotism.
 
If “being green” wasn’t hard enough, the number of different alternative fuel technologies emerging in the marketplace only serves to confuse the average commuter.  The most common green machine is the gas/electric hybrid engine, which power many coupes, sedans and SUVs on the market today.  (See the Vehicle Spotlight below.)   Hybrid vehicles run mostly on electric power provided by an extra large (and extra expensive) battery while you are cruising around town, typically providing 40-50 mpg fuel economy.   The gasoline engine kicks in at higher speeds (highway driving) and when extra power is needed, like under accelerating or towing.  Expect to pay around $4,000 more for a hybrid vehicle than for its traditional counterpart, but at least you will qualify for a nice tax credit.
 
Another common “alternative” fuel is diesel.  Like gasoline, diesel fuel is derived from petroleum, but it is denser, less flammable and easier to refine.  Diesel powered vehicles, while noisier, enjoy better fuel economy and lower emissions.  Diesel has been the fuel of choice in Europe and other countries, as well as for large trucks in the U.S. for many years.  More recently, a fuel known as “Biodiesel” has entered the market.  Biodiesel is derived from biological sources, such as vegetable oils, which can be used in most diesel engine vehicles.  Biodiesel is biodegradable, non-toxic, engine-cleaning, and produces 60% fewer carbon-dioxide emissions than regular diesel.  Unfortunately, Biodiesel has higher NOx (nitrogen oxide) and particulate emissions.  Biodiesel has become very popular in Europe and is gaining ground in the United States, with pumps in all 50 states.
  
E85 is an alternative fuel consisting of 85% Ethanol and 15% gasoline.  Ethanol is an alcohol-based fuel made by fermenting and distilling starch crops such as corn.  Ethanol is water soluble, non-toxic, and biodegradable and made right here in the U.S. of A.  Vehicles that run on E85, known as “Flex-fuel” vehicles, have lower carbon monoxide and carbon dioxide emissions than conventional gasoline or diesel vehicles.  Unfortunately, E85 has a low energy content which reduces fuel economy and engine performance.  President Bush and other Ethanol proponents say that’s a small price to pay to end America’s dependence on foreign oil.  For that to actually happen, we will need more E85 fuel pumps.  Currently, only 1000 of America’s 180,000 stations (mostly in the Midwest corn belt states) offer E85.

Which of these will alternative fuel contenders will emerge victorious and save us from economic and environmental disaster?  The jury is still out on that one.  Japanese automakers Honda and Toyota, who already make fuel efficient cars, are putting their money on hybrid technologies.  Honda offers the Civic and Accord in hybrid models, while Toyota offers the Camry, Prius, Highlander and several Lexus hybrids.  American giants Ford and GM are leading the E85 crusade and have invested heavily in research and development of the technology and infrastructure.  Daimler-Chrysler (Chrysler / Jeep / Dodge), Mercedes-Benz and Nissan also offer flex-fuel vehicles, for a total of 27 choices in 2007.   Not surprisingly, the European automakers, led by Volkswagen, are behind Biodiesel.  Any diesel engine vehicle, like the Beetle, Jetta, Golf and Tourag TDIs, can run on Biodiesel.

Each of these eco-friendly alternatives has challenges that must be overcome if the American public is to abandon gasoline entirely.  Hybrids will need cheaper batteries with greater capacity, and pure electric engines (plug-ins) still have a ways to go before they are a viable solution.  High NOx emissions threaten Biodiesel’s longevity, and E85 will need to become more available and less expensive before the price- and convenience-sensitive masses embrace it.  New technologies, such as hydrogen fuel cells and natural gas derivatives, are on the horizon and could provide solutions in the future.  Which will prevail?  Your guess is as good as mine.  Personally, I’m waiting for a car that runs on cat hair.  Now, there’s an endlessly renewable resource!  At least in my house.