[Chapter 9) Alternative Fuels and Additives
9.1) Do fuel additives work?
Most aftermarket fuel additives are not cost-effective. These include the octane-enhancer solutions discussed in section 6.18. There are various other pills, tablets, magnets, filters, etc. that all claim to improve either fuel economy or performance. Some of these have perfectly sound scientific mechanisms, unfortunately they are not cost-effective. Some do not even have sound scientific mechanisms. Because the same model production vehicles can vary significantly, it's expensive to unambiguously demonstrate these additives are not cost-effective. If you wish to try them, remember the biggest gain is likely to be caused by the lower mass of your wallet/purse.]
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[Is there anything I can add to my gas tank to increase mileage? Is there a device that will make a tank of gas go farther?
No, said Kirk Ready, professor emeritus at Minnesota State University, Mankato's Department of Auto and Manufacturing Engineering Technology.
Some additives could clean fuel injectors on a poorly maintained car, he said. But they are unlikely to improve fuel economy, given the sophisticated systems on today's cars, and the cleaning compounds already in gasoline.
Devices meant to be added to a car have not proven effective, Ready said.
One device, for example, is designed to get air swirling before entering the engine, to provide a better mix and better gas mileage. When tested, it made no difference in fuel economy or emissions, Ready said.
Some spark plugs supposedly fire more efficiently. But Ready said they have not been shown to increase fuel economy.
Synthetic motor oil provides up to a 2 percent increase in fuel efficiency over conventional oil. But synthetic oil is much more expensive than regular oil, and the amount of gas saved wouldn't make up the difference.
Ready also puts to rest the legend of cow magnets. Farmers put the little magnets (about the size of a cigarette) into the cow's belly on the theory that if the animal eats something metallic, such as a nail, the magnet will hold it in place, preventing damage or death to the animal.
Some have taped or clamped the magnets to automotive fuel lines in hopes of creating a magnetic field that supposedly would ionize the gasoline, leading to good fuel distribution, more efficient burning and improved mileage.
Ready said tests on magnets and similar commercial products, dating to 1973, find that they are ineffective.
However, there are two proven ways to improve gas mileage, Ready said.
? Reduce speeds. Driving closer to 60 miles per hour, especially on longer trips, will make your gas go farther, he said. In a motor home, for example, you'll get 15 percent more fuel efficiency just by reducing speed to 60.
? Inflate tires properly. Tires lose pressure over time, and underinflated tires burn up the gas. Keeping tires inflated to the car manufacturer's recommendations will make a gallon of gas go farther, but it makes tires last longer and improves safety, especially for SUVs and trucks, he said.]