These products are called Fuel saver chips, and they usually come in the form of a plastic device that plugs into the On-Board Diagnostics (OBD) port under your dashboard or in your engine ...

We have tested three: Fuel Genie, Platinum Gas Saver, and Tornado. Our advice: Don't waste your money. They don't work. This isn't news. We've tested such devices over the years and have repeated ...