100 octane fuel: avgas vs. racing gas

[Joel Bossard <jbossard@xxxxxxxxx>]

Hold on, Kent!
While Avgas does have a 100 octane variant, it ain't 100 unleaded racing fuel!

100 octane avgas is technically "100 LL" or Low Lead.  Low lead, in this
case is relative.
100LL avgas contains about as much lead as "regular" leaded fuel before
unleaded gas was mandated.  A bit less, but not much.  It's NOT for use in
cars as unleaded fuel, and will do all the nasty things to your motor and
cat's that any other leaded fuel will do.

100LL is low lead in comparison to the old 115/145 avgas, which was
ultra-high octane, heavily leaded (some say you could barely see through
it) fuel. After helping us win WWII (really) it was cheap and plentiful
till about the 1972 fuel crisis. This was "the juice", that you could put
in Pop's 'ol Dodge, crank the timing up 20 degrees, and go kick tail at the
drive-in drags.  Generally it is no longer available.

Real unleaded racing, or high-octane gas, is the way to go.  The Sunoco
product is probably the best, racing fuel from race tracks may have some
lead in it.  Let's face it, real racers done care about the lead, just
horsepower.

James Clay didn't say what problem he was trying to solve.  An off-road
racer can use leaded racing fuel, if available.  A street car that needs
100 octane fuel to cure some condition is probably, uh, broken.

Please don't pour the 100LL "blue juice" in your car with out considering
the above.
HTH,

- - Joel Bossard
98 M3/4
Private Pilot, Single Engine Land  

> ------------------------------
>
> Date: Thu, 10 Dec 1998 16:00:05 -0500
> From: James Clay <jclay@domain.elided>
> Subject: 100 octane fuel needed
>
> I live in Blacksburg, VA, which is about 2 hours from Charlotte, 3.5
> from NoVA, and 3 from Richmond.  I am looking for 100 octane gas
> containing no lead.  Would someone please let me know if it is available
> anywhere within 3-4 hours.
>
> Thanks
> James Clay
>

>Then Kent Shaw writes>

>You can probably get 100 octane unleaded at your local airport (i.e.
Virginia Tech).
>Some of the weekend drag racers use aviation fuel instead of the auto gas
sold at the
>speed shops because aviation fuel is about $1 gallon less.  Gas with 130
octane low
>lead is more common, but many of the airports stock lower octane for some
of the older
>planes that were designed to use it.  Make sure that your compression
ratio can
>accommodate high octane fuel else detonation may cause engine damage and I
don't want
>to be responsible!.

>Kent Shaw

Joel Bossard
98 M3/4

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