[Biturbos4] Detecting 95 and 98 RON setting?

Ti Kan ti at amb.org
Tue Sep 7 21:43:51 EDT 2004

Andy Turner writes:
> I believe my 2000 Audi S4 switches various timings whenever I put
> super unleaded (98 RON) petrol in. However, I've never found 98 RON to
> make much difference in performance - if anything. Is there something
> I can look at with my VAG-COM to determine whether the car has decided
> that it's now on the 98?

I don't think it detects the fuel, but the knock sensors will cause
the ECU to dynamically adjust ignition timing to prevent any knock.
Running higher octane fuel will allow the ECU to run the engine with
more ignition advance and provide better performance.  I believe
you can watch the ignition advance in a semi-real-time basis using VAG-COM,
but I don't remember which measuring block it was.  You'll probably
find some info on this in the VAG-COM list archives:

 R 1 3 5  Ti Kan
 |_|_|_|  http://www.amb.org/ti
   | | |  Vorsprung durch Technik
   2 4 6

More information about the Biturbos4 mailing list