some ahve claimed that until the car warms up, it runs like you-know-what. Several have claimed that the dealers tell them to run 89-90 octaine in the winter. Any reason why this is good or bad?

I know, the manual says stick to premium, and to date I have only put Mobil Super or Shell V-Power in my car. Thoughts?

Just kidding, I am curious too. I am sure someone will chime in.

would be amazed if this cures your poor cold start conditions. The poor cold start "stumbling" of the engine is likely caused by those who do not drive enough distance to get the engine fully warmed up and the plugs up to self-cleaning temp. I would advise against this as IMO the lower octane gas would make this situation worse instead of better.

I mean is yr engine running bad now? otherwise the 2.7tt engines have 4 knock sensors. The ECU can retard ignition enuf not to cause any damage. You can run some pretty crap gas in there as long as yr not heavy in the throttle.<ul><li><a href="http://www.chevron.com/prodserv/fuels/bulletin/motorgas/1_driving-performance/pg4.asp">get smaaaaaaaaaaaaart here</a></li></ul>

respones to go to lower oct. and I tried it and it worked! I was running 93 and dropped to 91, some said to mix tankfuls, 89 then 93. Since these cars run on that crappy CA. 91 I wasn't bothered by dropping to midwest 91. All I can say is it worked very well for me and I had no problems!

Here is some other veiws and one RS6 owner that uses 91!<ul><li><a href="http://forums.audiworld.com/a6/msgs/450885.phtml">clicky</a></li></ul>