back in hard times, I bought a camry to save some money and I think its time to come back into the audi fold. Not sure if I want to go A3 or A4 (or if the wife it up to it... TT). The back seat on the A3 is small for anyone over like 6 foot.

I am 6'1" and where I have my seat I can sit very comfortably in the back seat. Only people have had have in the back for long trips though were short.

<center><img src="http://pictureposter.audiworld.com/63004/pc280028.jpg"></center><p>But here in Southern California, 91 is the top of the line. I never see 93 octane pumps unless I'm out of state.

I will say headroom was close for me but not terrible.

Even before states stopped carrying things higher then 91, it was always still the minimum required on cars needed premium. In most cases it would be better if 99% of people running premium had 91 not 93...You can lose performance with more octane if the car can't take advantage of it.

post Enron, I just wanted to get away. My wife if from here as well.

The point of going to a higher octane gas is to prevent detonation and pre-ignition. How does the higher octane do this? By making itself harder to ignite. It takes more engergy to ignite higher octane gas. It is not the octane that is making the power.. it is the octane that is allowing you to cram more air in or run more timing without having negative effects. If you can run 15psi and 20 degrees of advance on 91 octane without having any problems with detonation or pre-ignition then running 100 octane won't give you anymore power.. but it can actually harm power becuase what is used to increase that octane may not contain as much energy as the 91 octane.

Example running say 100 octane in a car tuned to run on 93 that is running perfectly right like that with no timing being pulled by the knock sensors or intake temps may actually sputter and make less power with the 100 octane.. I"ve seen this many times and experienced it myself.

Now however if your car is not running optimally, or rather it is pulling timing or pulling boost running the higher octane may give you an increase in power only becuase the car is now able to run the timing and boost that it wants.. not becuase the higher octane is adding any power.

this but this is the first I've heard a possible loss in performance. You noted "You can lose performance with more octane if the car can't take advantage of it." I'm wondering whether older vs. newer vehicles has anything to do with this or does that not have any relationship to this?

I'm just trying to comprehend why some cars may "take advantage" of the higher octane while others may not.

New vechicles since they are more computer controlled can safely try and push the limits persay and see what happens. Howver there is still a point where it wont' try to advance the ignition any further or run more boost. If the did have unlimited advance there would be no need for chips programmed for high octane fuel.