Re: Fuel Additives (JMTombstone)
I would stay away from that stuff. Not worth the money.
Stick with a top tier gas and your good.
http://www.toptiergas.com/retailers.html
Here is why.
Most aftermarket fuel additives are not cost-effective. These include the
octane-enhancer solutions. 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.
There is one aftermarket additive that may be cost-effective, the lubricity
additive used with unleaded gasolines to combat exhaust valve seat recession
on engines that do not have seat inserts. This additive may be routinely
added during the first few years of unleaded by the gasoline producers, but
in the US this could not occur because they did not have EPA waivers, and
also may be incompatible with 2-stroke engine oil additives and form a gel
that blocks filters. The amount of recession is very dependent on the engine
design and driving style. The long-term solution is to install inserts, or
have the seats hardened, at the next top overhaul.
Some other fuel additives work, especially those that are carefully
formulated into the gasoline by the manufacturer at the refinery, and
have often been subjected to decades-long evaluation and use [12,13].
A typical gasoline may contain [16,27,32,38,111]:-
* Oil-soluble Dye, initially added to leaded gasoline at about 10 ppm to
prevent its misuse as an industrial solvent, and now also used
to identify grades of product.
* Antioxidants, typically phenylene diamines or hindered phenols, are
added to prevent oxidation of unsaturated hydrocarbons.
* Metal Deactivators, typically about 10ppm of chelating agent such as
N,N'-disalicylidene-1,2-propanediamine is added to inhibit copper,
which can rapidly catalyze oxidation of unsaturated hydrocarbons.
* Corrosion Inhibitors, about 5ppm of oil-soluble surfactants are added
to prevent corrosion caused either by water condensing from cooling,
water-saturated gasoline, or from condensation from air onto the
walls of almost-empty gasoline tanks that drop below the dew point.
If your gasoline travels along a pipeline, it's possible the pipeline
owner will add additional corrosion inhibitor to the fuel.
* Anti-icing Additives, used mainly with carburetted cars, and usually either
a surfactant, alcohol or glycol.
* Anti-wear Additives, these are used to control wear in the upper cylinder
and piston ring area that the gasoline contacts, and are usually
very light hydrocarbon oils. Phosphorus additives can also be used
on engines without exhaust catalyst systems.
* Deposit-modifying Additives, usually surfactants.
1. Carburettor Deposits, additives to prevent these were required when
crankcase blow-by (PCV) and exhaust gas recirculation (EGR) controls
were introduced. Some fuel components reacted with these gas streams
to form deposits on the throat and throttle plate of carburettors.
2. Fuel Injector tips operate about 100C, and deposits form in the
annulus during hot soak, mainly from the oxidation and polymerisation
of the larger unsaturated hydrocarbons. The additives that prevent
and unclog these tips are usually polybutene succinimides or
polyether amines.
3. Intake Valve Deposits caused major problems in the mid-1980s when
some engines had reduced driveability when fully warmed, even though
the amount of deposit was below previously acceptable limits. It is
believed that the new fuels and engine designs were producing a more
absorbent deposit that grabbed some passing fuel vapour, causing lean
hesitation. Intake valves operate about 300C, and if the valve is
kept wet, deposits tend not to form, thus intermittent injectors
tend to promote deposits. Oil leaking through the valve guides can be
either harmful or beneficial, depending on the type and quantity.
Gasoline factors implicated in these deposits include unsaturates and
alcohols. Additives to prevent these deposits contain a detergent
and/or dispersant in a higher molecular weight solvent or light oil
whose low volatility keeps the valve surface wetted [46,47,48].
4. Combustion Chamber Deposits have been targeted in the 1990s, as they
are responsible for significant increases in emissions. Recent
detergent-dispersant additives have the ability to function in both
the liquid and vapour phases to remove existing deposits that have
resulted from the use of other additives, and prevent deposit
formation. Note that these additives can not remove all deposits,
just those resulting from the use of additives.
* Octane Enhancers, these are usually formulated blends of alkyl lead
or MMT compounds in a solvent such as toluene, and added at the
100-1000 ppm levels. They have been replaced by hydrocarbons with
higher octanes such as aromatics and olefins. These hydrocarbons
are now being replaced by a mixture of saturated hydrocarbons and
and oxygenates.
If you wish to play with different fuels and additives, be aware that
some parts of your engine management systems, such as the oxygen sensor,
can be confused by different exhaust gas compositions. An example is
increased quantities of hydrogen from methanol combustion.
Chew on that for a bit, may make you decide not to throw in a can of this or that int he tank.
