Date:         Tue, 18 May 1999 10:45:01 -0700
Reply-To:     daveb@CP.NET
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Dave Bayer <daveb@CP.NET>
Subject:      How do anti-ping additives work?
Content-Type: text/plain; charset=us-ascii

I know we used to have someone who worked for one of the
big gas manufactures on the list... Maybe someone can help
me with this...

I am trying to figure out if anti-ping additives merely slow
the burn rate of the fuel-air mixture or actually just increase
the charges' resistance to detonation (and if it does the latter,
how does it accomplish this).

The reason I am asking is that I am trying to figure out why
some engines with kncock sensors require "premium" gas. I am
also trying to figure out if there is any truth to the
statement that running regular gas in say an Audi engine would
retard the timing and therefore reduce the power the engine
puts out (the arguement was that since the timing was delayed,
the enigne would lost power - which does not make sense to me
because the lower octane gas will complete its burn quicker
than the premium stuff anyway thus offseting the delayed
spark).... Of course, that is my "logically" view of a system
I know little about.

Anyway, knowledge on this is greatly appreciated...

dave