Max is absolutely correct.
You only need avgas if you have a higher compression ratio or
your timing is more advanced than "normal".
However, avgas does burn far more cleanly than regular pump fuel.
I can see the difference when I pull down my race motor and compare it
to my road motor.
avgas is also mighty handy for cleaning parts because unlike conventional
petrol (gas) it leaves no residue at all.
Mike
-----Original Message-----
From: Max Heim <mvheim@studiolimage.com>
To: MG List <mgs@autox.team.net>
Date: Friday, 28 May 1999 5:56
Subject: RE: AVGAS to be phased out!
>Umm, don't mean to contradict you, but unless you are 1) "knocking" or
>"pinging" on regular fuel (other than Avgas); 2) advancing your timing
>after you fill up with Avgas, and retarding it when you fill up with
>regular; or 3) driving a modern car with computerized knock sensing and
>advance, there will not be any performance improvement in running higher
>octane fuel. Period. This has been stated in SAE literature, and was the
>subject of a class action suit in California against the oil companies.
>The companies were found guilty of deceptive advertising when their ads
>encouraged customers to buy their premium grades for "better
>performance". Basically, it was found that as long as you were running
>fuel of a high enough octane to avoid "pinging", a higher grade of fuel
>had no beneficial effect; unless, as I said, the computer sensor could
>then advance the timing to take advantage of it.
>
>This perception of better performance is a fallacy encouraged by the oil
>companies, who are only interested in your money. Of course, if you
>retune your car each time you fill up to take advantage of the higher
>octane, then you would benefit. But who does?
>
>Flame suit at the ready...
>Max
>
>>> A number of individual States of Australia have already restricted or
>>> banned this fuel for use on "public roads" under 'clean air'
>>> legislation. Whilst in many cases this mean that people racing on
>>> tracks can still use it (for now) rally drivers who must travers 'public
>>> roads' cannot! I don't suppose that stockpiling fuel in the backyard is
>>> an option but this is a pity because I have found that my little car
>>> REALLY enjoys the occasional full tank of AVGAS and more frequently the
>>> half/half mix. I do notice the better performance (and besides... it
>>> smells great :-)
>
>>> Eric
>>> '68MGB MkII
>>>
>>
>>
>
>
>--
>
>Max Heim
>'66 MGB GHN3L76149
>Runs great,
>looks particularly bad since some SUV clown backed into it.
>If you're near Mountain View, CA,
>it's the red one with the silver bootlid.
>
>
|