I was inspired to do some research on this subject after encountering
a fellow selling these things at the local boat show. What attracted
by attention wasn't the guy from Florida peddling the devices, but a
well-known and respected local company representing it as well.

I would not go so far as to say that these things work, but it may not
be beyond the
realm of possibility and if they do work the following item attempts
to explain why.
There are a lot of references available on this, by the way. Key
search terms would include
"diamagnetic", "orthodydrogen", "parahydrogen", and "ferromagnetic"
and "paramagnetic".

*******

Can a Fuel Magnet be an Attractive Device?

The concept almost defies common sense. "Run your diesel fuel over a
magnetic conditioner en route to the engine, and it will burn cleaner
and more efficiently."

Skeptics can be easily forgiven for observing, "I can dip a magnet
into diesel fuel and not even one drop is going to stick to the
magnet, so how can anybody make a case that diesel fuel is affected by
magnetism?"

We happened across a display at the recent boat show, where at device
known as the Diesel-Tex DTX diesel fuel conditioner was being
demonstrated by the manufacturer. We noticed that the product is sold
in the Pacific NW by [deleted for newsgroup], and as they're a
respectable firm with a very good reputation we assumed there must be
some merit to the concept of magnetically conditioning diesel fuel.

After spending an evening researching the idea on the internet, we
discovered some interesting basics about magnetism and fuel that may
allow a credible case to be made for a concept that sounds, on the
surface, like a snake-oil pitch.

We found hundreds of references confirming that nearly all materials
are affected by magnetic fields. The reactions to exposure to a
magnetic field can be categorized as diamagnetic, paramagnetic, and
ferromagnetic. Every schoolchild is familiar with ferromagnetic
reaction, and has experimented with attracting steel and iron objects
to a bar or electro magnet. Ferro magnetic materials are highly
susceptible to a magnetic field, and can even become permanently
"magnetized" once the original magnetic field has been removed.

Simply because we cannot see diamagnetic and paramagnetic reactions
doesn't mean they aren't equally real. (I've never personally seen
"electricity", but I have to believe it exists). The differences
between diamagnetic and paramagnetic reactions consist primarily of
how the magnetic field affects the electrons in an atom.

As an electron rotates around the nucleus of an atom, it creates a
magnetic field.
Electrons most frequently occur in pairs, and rotate in opposite
directions. The opposite rotations create two opposing magnetic fields
that cancel one another out, so most materials have net magnetic field
of zero. Magnetic fields will realign the electron orbits of any
element. Diamagnetic materials have all electrons in pairs and react
negatively to a magnetic field. Paramagnetic materials have some
electrons that are not offset by an opposing half of a pair, and react
positively to a magnetic field. The key concept to appreciate is that
virtually every element on the periodic table will react either
positively or negatively to a magnetic field, even if we don't see a
dramatic attraction like we expect with ferromagnetism.

Diesel oil is a hydrocarbon that is about 84% carbon and 16% hydrogen
by respective weight. Even though the hydrogen is only 16% of the
hydrocarbon molecule, it produces about 45% of the thermal energy
extracted by combustion. Common hydrogen separates into parahydrogen
and orthohydrogen when subjected to any electrical influence or
magnetic field that will realign the orbits of its electrons.
Orthohydrogen is more reactive than parahydrogen and is able to
attract additional oxygen molecules.

The theory of magnetic diesel fuel treatment states that exposing the
diesel fuel to the magnetic field will increase the ratio of
orthohydrogen atoms that can be additionally oxygenized to promote
more complete combustion, extraction of energy, and a reduction in
unburned fuel molecules in the exhaust.

An additionally claimed benefit of magnetic diesel fuel treatment is
the elimination of microbial organisms from the fuel. This is
apparently accomplished by disrupting the balance between the positive
and negative electrical charges found within and immediately
surrounding each cell, resulting in perforating the cellular membrane
and killing the organism.

Do magnetic fuel conditioners work? We aren't in a position to state
from personal experience that they absolutely do or do not, but
growing numbers of boaters are reporting positive results from the
installation of Diesel-Tex diesel fuel conditioners. Cleaner transoms,
less exhaust smoke, and better engine performance are frequently
mentioned in testimonial letters on the Diesel-Tex website,
(www.dieseltex.com). Most testimonial letters appearing in marketing
campaigns are printed with initials instead of signatures, but the
letters on the Diesel-Tex site tend to offer the full name, address,
phone number, and email address of the person offering to share their
personal experience. That fact tends to inspire some credibility, and
if our evening's research has led us to the right conclusion there is
no reason to believe that magnetism cannot affect diesel fuel or that
such effects could not include modifying parahydrogen to the more
combustible orthohydrogen.