[BiturboS4] RE: gasoline
dano at well.com
Fri Oct 25 09:27:08 EDT 2002
I'm late to this thread...new job and overloaded with work, way
behind catching up on email...
Walter Green "self moderated"??!!! bwahahahah!
At 1:59 PM -0700 on 10/17/02, California Fields wrote:
>Good points, Ti. Recently, though, all of the "76" gas stations in California
>offer their gas WITHOUT any MTBE. They are the first to do so. I think this
>is because of the overwhelming evidence that MTBE has polluted groundwater
>(and it has marginal benefits for tailpipe reductions).
MTBE (methyl tertiary butyl ether) was mandated by CalEPA some years
ago as a replacement for benzene and instead of ethanol (aka EtOH)
which corrodes the hell out of many automotive components.
The reasons for these chemicals are... Benzene helps accelerate
combustion, but is extremely carcinogenic. (One of the few chemicals
that is actually a proven carcinogen, so it's a nasty thing to have
around lackadaisical consumers and their children (i.e. self-serve
gas pumps). Think about this latter fact the next time you're pumping
gas and are 1 meter downwind from the fumes emanating from the nozzle.
Another way to accelerate combustion is by using a combustible liquid
fuel that has an oxygen molecule in it; these are known as
oxygenates. EtOH is pushed hard by our friends Archer Daniels Midland
because they grow millions of tons more corn (US government
subsidized) than the world can use, and they need to create a market.
But ethanol is corrosive to many fuel systems and other rubber parts.
Not good to have all those rubber gaskets leaking highly combustible
fuel inside an engine compartment.
MTBE is not nearly so corrosive but is oxygenated. Unfortunately (and
just like EtOH) it is also highly hydrophilic. Unfortunately many UST
systems (underground storage tanks) leak, and when MTBE
leaks out of USTs into ground water it is impossible to remove. (Not
'almost' impossible. It costs so much money and cannot be completely
removed anyway.) It dissolves into the water and stays there. It also
smells strongly even at low concentrations, so it's very apparent to
the human nose. It probably has some level of toxicity, but I don't
know about that.
Most components of gasoline are hydrophobic so when they leak out of
the USTs they don't get into the water supply. (EtOH will also, but
in that case you're just adding a bit of "octane" to your scotch and
So MTBE was a good idea in that it replaced benzene, but in practice
it was a bad thing because the gasoline delivery infrastructure was
not equipped. California has some drinking water wells that are
polluted for (probably) many years by MTBE. And it still has not
solved the problem of getting better combustion.
(Note that leaded fuels increase combustion also, but they inject
lead into the environment. That is a Bad Thing also.)
There's more to the story, but I gotta go... :-)
>I fill up at "76"
>only and encourage all of my California friends to do so. Unfortunately, the
>highest octane is still only 91.
>On that note, anyone know where I can get higher octane gas in the Bay Area
>(San Francisco)? Do I have to buy race fuel or can I purchase some sort of
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