Mid Grade gas vs High Octane gas - better performance??

[mabatzis at gmail.com (Michael Abatzis)]

like i said, IF it's knocking on regular, the timing will be retarded.
 however, otherwise it will run the same.  and the timing that you set
(at least on the cis-e's) doesn't affect it at all; you're only
setting the idle timing.  the computer sets the final timing under
load (32' or something), which is independent of what the static
setting is.  the knock box only comes into play if knock is detected,
at which point the timing is temporarily retarded.  it attempts to
re-advance the timing if no more knock is detected up to the
computer-determined limit.

On 3/14/07, Peter <peter@thescirocco.com> wrote:
> I found the opposite when I had a company gas card.
>
> My 16V ran better, and got better mileage on high octane.
>
> BP's 92 octane wasn't enough for my 16V, with the timing set to stock.
>
> The 16V's need high octane fuel to run at it's optimum, and it made a
> noticible difference to me.
>
> The knock box retards the timing, where as advancing it would makle it ping
> even more.
>
> Peter
>


-- 
-Michael Abatzis
New Orleans!
'88 2.0L Scirocco (RIP)
'87 2.0L Scirocco...(RIP also)
'91 Saab 900t convertible...