These devices insert pieces of various metals into the fuel. The claim behind them is that the metals produce a catalytic reaction in the fuel, removing impurities and making it a more efficient energy carrier. Some of these devices even claim to remove harmful bacteria from the fuel.
The merits of these devices are hard to measure without the aid of a mass spectrometer or other equipment that can measure the chemical changes that might take place in the fuel. But this could all be a moot point, given another factor: Modern engines are optimized to run on modern fuel in its current state. Changing that state moves the fuel away from the optimal fuel the engine is designed to burn. This may only be a minimal change, but it still strays from the standard engineered into the engine and its control systems. If the catalyzed fuel does indeed have properties that make it burn cleaner or faster, the engine's controls may not be able to adapt in a way that realizes any mileage improvements [source: Tony's Guide to Fuel Saving Gadgets].
For more information on saving fuel and related articles, check out the links below.
- Allen, Mike. "Looking For A Miracle: We Test Automotive 'Fuel Savers.'" Popular Mechanics. Aug. 25, 2005. (June 12, 2011) http://www.popularmechanics.com/cars/alternative-fuel/gas-mileage/1802932
- Alternative Energy News. "Hydrogen Fuel." (June 21, 2011) http://www.alternative-energy-news.info/technology/hydrogen-fuel/
- Herning, Garrett R. "Singh Groove Concept: Combustion Analysis using Ionization Current." AutoTronixs, LLC. October 2007. (June 21, 2011) http://www.herningg.com/singh/Ionization%20current%20analysis.pdf
- RallyCars.com. "How a water injection system works." (June 20, 2011) http://www.rallycars.com/Cars/WaterInjection.html
- Tony's Guide to Fuel Saving Gadgets. "Fuel 'saving' gadgets." (June 12, 2011) http://www.fuelsaving.info/debunk.htm
- U.S. Department of Energy. "Gas Mileage Tips." (June 22, 2011) http://www.fueleconomy.gov/feg/drive.shtml
- U.S. Environmental Protection Agency Office of Mobile Sources. "Tips to Save Gas and Improve Mileage." August 1994. (June 12, 2011) http://www.epa.gov/oms/consumer/17-tips.pdf
- Valdes-Dapena, Peter. "6 gas-saving myths." CNN Money. Aug. 12, 2008. (June 12, 2011) http://money.cnn.com/2008/05/12/autos/ways_to_not_save_gas/
Does stop-start technology really help with fuel economy? HowStuffWorks talked to experts to find out.