fuel saving devices
source: http://www.aa1car.com/library/gas805.htm
My Advice on Gas Saving Gadgets
As I write this article, the price of regular grade 87 octane gasoline is between $4.19 and $4.25 a gallon in the metro Chicago area. The huge jump in fuel prices is hitting motorists hard and people are looking for ways to reduce their fuel costs. Some are trading in their big gas-guzzling SUVs for smaller vehicles. More people are using public transportation and car pooling (both of which are almost as painful as paying more at the pump). And some are falling victim to con artists who sell gas saving gizmos that promise huge fuel savings.
As PT Barnum once said, "There's a sucker born every minute." So don't fall for the con artists lies. Forget the gas saving gizmos because none of them work!
Every gas saving gadget I've seen to date does absolutely NOTHING to improve fuel economy. In fact, some of them actually reduce fuel economy.
Products that claim to magnetize or polarize gasoline molecules, or realign the molecular structure of the fuel for more efficient combustion (cow magnets and similar gadgets), or devices that claim to ionize the spark for better mileage are pure nonsense and are based on false science. Such devices have been tested repeatedly by the EPA and independent test labs, and every test found ZERO change in fuel economy.
What about devices that swirl air entering the throttle body and "supercharge" your engine? These devices are installed in the air inlet system and have a blade that supposedly swirls the incoming air to improve fuel atomization for more efficient combustion. Baloney. Several car magazines have tested these devices and found they actually REDUCE horsepower and fuel economy by creating a restriction in the air intake system.
What about the infamous 200 mpg carburetor? By vaporizing the fuel, this carburetor is claimed to deliver 200 plus miles per gallon on any engine. Pure urban legend. Check it out on Snopes. Actually, direct fuel injection vaporizes the fuel as it enters the combustion chamber, delivering 15 to 20% better fuel economy over ordinary electronic fuel injection. But you can only get it on a few engines. More new engines will have this system as time goes on.
What about running your car on hydrogen gas? The "HHO Hydrogen Generator" devices that are being peddled on the internet that convert water into hydrogen gas with electricity can't produce enough hydrogen gas to run a lawn mower engine, let alone an automobile engine. The little bit of hydrogen that fizzles out of these things won't make any difference on your mileage either, though the promoters of these mileage saving devices claim dramatic improvements in fuel economy. They claim the hydrogen "supplements" the fuel supply so your engine doesn't need as much gas. It seems logical, but the volume of hydrogen produced by these devices is so small that it has little or no measurable effect on fuel economy.
ONE GADGET THAT ACTUALLY WORKS
One gas saving gadget that can improve fuel economy is a simple vacuum gauge. The gauge displays intake vacuum, which is an indication of how much load is on the engine. The lower the vacuum reading, the higher the load on the engine and the more fuel it burns.
The gauge saves gas by helping the driver see the effect his right foot has on fuel consumption. Tromp down on the gas pedal and intake vacuum drops and fuel consumption goes up. Take it easy on the gas pedal and accelerate slowly causes less of a drop in intake vacuum and less fuel usage. Duh!
A more hi-tech version is a fuel economy meter that plugs into the OBD II diagnostic connector on 1996 or newer vehicles. The unit displays instantaneous fuel mileage and cumulative fuel mileage like a trip computer on on a vehicle equipped with this option.
FUEL ATOMIZATION
Back in the days when carburetors were used to feed gasoline into the engine, there were a couple of tricks that could improve fuel economy a bit, especially when the engine was cold. One was a simple honeycomb spacer that fit under the carburetor. The turbulence created by the honeycomb helped break up the fuel a bit. Another was an ultrasonic vibrator that mounted under the carburetor. The vibrator also improved fuel atomization slightly -- but only provided a marginal benefit when the engine was cold.
Some engines from that period used an electrically heated grid under the carburetor to improve fuel atomization following a cold start. But like the other devices, the benefit disappeared once the engine reached normal operating temperature.
Today's fuel injected engines atomize the fuel when they spray the fuel into the engine. They don't need intake manifold heaters or other such devices. The most efficient designs are the new high pressure "direct injection" systems that VW uses on some of its engines.
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fuel saving devices
