回複：then, why they still sell them?

I am using some other mixes here, I got it from C&D article on Jan 09', page 97: it works only if you know your vehicle. After six months using it on my 96' Accord and 02' WRX, no any negative phenomena noticed. Here is the whole paragraph from C&D:

Best Fuel-Saving Act of Desperation
From C & D Jan. 2009, Pg. 97

I was an industrial diesel mechanic for 18 years. Here's the gas-stretching method
I've been using for about 20 years.
1. Get a sturdy, thick, clear-plastic quart bottle, thicker than a water bottle, with
a screw-on cap.
2. Add naphthalene monthballs (must be naphthalene only, not para-diachlorobenzene!)
to fill the bottle to the top of the neck.
3. Add one eight-ounce bottle of fuel-system cleaner (such as fuel-injector or carb
cleaner, or the sort of cheap gas additives you can find at Wal-Mart for about $1 a
bottle).
4. Add eight ounces of liquid WD-40 (hardware stores sell it in gallon cans for $12 to
$15; that's about $1 per treatment).
5. Let it sit for a few days.
6. Add one bottle of the mix to your tank with a funnel and a small screen filter each
time you fill up. It will only work with 92-octane fuel (never tried regular fuel).
Use it every time you fill up.

What it does: The fuel-system cleaner breaks down the mothballs, which turn into liquid
and dissolve, making an octane booster. The WD-40 displaces water in ethanol and keep
all the fuel-system components very clean, and it displaces moisture at the bottom of
the fuel tank. It also raises the octane of your fuel. Naphthalene is a byproduct of
gasoline producton (used as drag racing fuel) and has a much higher combustion rating
than gasoline. One professional mechanic here said the mix is about 107 octane. MOre
power, more bang for your gas buck!
I have always gotten 10-to-20-percent-better mileage using this mix. I have 45,000
miles on a Honda CR-V with no problem involving emmissions or its catalytic converter,
no ring "blowby" or funny smells. I get about 10 percent more power and about 5 more
mpg. Never had to clean the injectors on my Civic for 240,000 miles or had any fuel
or computer problems! Seems to work better on four-cylinder engines and costs about $3
a tankful. The mothballs will last about 10 fills before they completely dissolve. Just
keep adding fresh ones to the bottle.
Try it--I swear it works--But you really have to know your vehicle to notice the
diference, and it may not be noticeable with six- or eight-cylinder engines. I get about
30-31 mpg in the CR-V with this mix and about 10 to 15 percent more power with sensible
driving. Save the fuel-cleaner bottles to store your mix. Make it in big batches.

Bill ROmerhaus
Haleiwa, Hawaii