When gas prices go up, the scam artists show up. Products that claim to boost gas mileage are bogus, according to the EPA. After testing hundreds of “mileage maximizers,” the EPA says it “has not found any product that significantly improves mileage.”

So whom do you trust when it comes to getting the best fuel mileage your car or truck can achieve? Your dealer’s service department, that’s who! There’s a reason the manufacturer publishes a recommended service schedule. These intervals are derived from the manufacturer’s engineering and testing to determine what is necessary to maintain the performance of key components. The best way to get the best mileage is to maintain your vehicle according to the manufacturer’s service schedule. The best way to maintain your vehicle is factory authorized service using original equipment parts.

If you really want to squeeze more miles out of every gallon of gas, slow down, make sure your tires are properly inflated, change your air filter if it's dirty, combine trips, don’t let your engine idle longer than a minute and stop those “jackrabbit starts” and “dig-in-the-heels” stops. Whatever you do, don’t fall for one of those mileage booster scams.

Oh, they are tempting! Those advertising writers can make performance claims sound authoritative and the underlying “technologies” compelling. There is no pill, magnet, atomizer, ionizer, vapor injector, preheater, gasification, conditioner, spritzer, coil, turbo, extractor, air bleed or vortex generator technology that has ever delivered on its mileage improvement promises.

Over the years, the U.S. Environmental Protection Agency has tested a myriad gas-saving devices that have burst onto the consumer scene - devices that bleed air into the carburetor or bubble air through a container of water and antifreeze mixture, fuel-line gadgets that heat the gas before it enters the carburetor, magnets that clamp to the inside or outside of the fuel line to change the gasoline's molecular structure and metallic fuel-line additives with dissimilar metals that claim to ionize the fuel.

Experts say they all have one thing in common. "They don't work," says John Millett, spokesman for the EPA. "Believe me, if it were that easy, cars would be built that way, especially the magnets and whirligig devices. It's smart to be skeptical about any claims like that."

The EPA to date has tested in the neighborhood of 100 gas-saving devices, the most recent at the request of the Federal Trade Commission, and only six "indicated a very small improvement in fuel economy without an increase in exhaust emissions."

Another four also made the itty-bitty improvement cut, but, per federal regulations, the exhaust emission tradeoffs mean consumers who slap these on their cars could face charges of illegal tampering.

Popular Mechanics magazine's experts tested seven fuel-saving products and found no significant change in miles-per-gallon ratings. Two actually increased fuel consumption by 20 percent, according to the writer, and a third one melted before they could complete the test.

But none of the debunking or warning stops the ambitious scammer bent taking advantage of people who are fed up with low mileage and high gas prices.

Some of the claims go beyond wild and into the area of fraud:

• "This gas-saving device is approved by the federal government." According to the FTC, no government agency endorses gas-saving products for cars. The closest they can come to truth in advertising is to say that the EPA has reached certain conclusions about possible gas savings by testing the product or evaluating the manufacturer's own test data.
• “The automobile manufacturers don’t want you to know about this breakthrough technology that boosts power and mileage.” The fact is, manufacturers are spending millions of dollars on ways to improve the fuel efficiency of their engines and cars. If there was a breakthrough, you can be sure they would install it on every vehicle they make.
• “The petroleum industry is using fuel manipulation in order to reduce gas mileage and pad their profit margins. Only the “Fuel Optimizer” is capable of concentrating octane power before it reaches the combustion chamber.” Hooey! The petroleum industry doesn’t need to employ a conspiracy to pad its profits. Supply and demand will do nicely, thank you very much.

Another myth that scammers love is the claim that higher octane means higher power. Here’s one of the actual claims: “Super Gas Drops Will Make Pump Gas Think It's Race Fuel. Everyone knows that high octane racing fuel or aviation gas makes their bike, jet ski, or ATV perform better than pump gas. One Eyedropper Of Super Gas Drops Is All You Need To Make One Gallon of Low Octane Pump Gas React Like Race Fuel!” WRONG! An engine designed to run on regular unleaded will not experience a power boost if you put premium gas in the tank. Use the fuel grade specified by the manufacturer—nothing less and nothing more.

Conclusion? The old adage that “something that sounds too good to be true, probably is” nearly always applies. So, don’t be “fuelish” and let those scammers put one over on you.