quote:

ORIGINAL: TacticalH3

Thanks for your imput!

It looks like I will stick to atleast 89. As for my warrant, it is just what I'm use to. I came from vehilces that required 93 octane. Anything less, it would not perform well. I'd figure that putting in 93 would yield better results to the "inferior" 87. My reasoning is not scientific either. Is there any oil/gas gurus here?

quote:

ORIGINAL: audil

I don't believe for a second that higher octane does not affect the cars performance. Sure, that's what the TV reporters says (that you are supposedly wasting money on premium gas, that low or mid-grade is just fine for all non-high performance vehicles). Just from previous experience, I've had a very nice Audi S4, which was very well maintained and taken care of, and had about 10K miles on it by then, thus in top performance shape. As I drove from California to Midwest, the octane up until about Missouri is actually 91 (92 if you can get Sunoco). Only in Missouri or so, the premium octane switches to 93 octane (94 at Sunoco), like it is on the East Coast. Well, the additional 2 octane did make a very noticeable difference -- the car was definitely reacting, accelerating better - that's despite the fact that it already had a very good acceleration, and that despite the twin-turbo's, it always had a small but predictable lag. Also, the ECU did not yet had time to adjust itself to higher octane and potentially slightly different driving style. Yet, the fact remains, just a simple switch from 91 to 93 octane made a very noticeable and immediate difference to a driver, who was very sceptical about all this and at the time believed those reports that octane doesn't matter. By the way, the car's manual said to put at least 91 octane in US, or 95 if in Canada (or Europe for that matter, where most such premium cars use 95 octane, whilst sports cars use 98 octane, which is also widely available to all gas filling stations).

An acquaitance of mine, who is a big car buff (has one rebuilt muscle car with about 700 HP) and a co-owner of a premium car/limo rental service, always told me that he periodically mixes higher octane into all his cars even if they say 87, just to "clean the pipes".

So the bottom line is, octane does matter, at least in my experience.

And like someone else said, Shell gas is indeed very good. I've been using it in 90% of the cases for the past 8 years, and it does seem to me that their marketing campaign is truthful, and their gas if not superior, then at the very least very good and trouble-free. But then all depends on the gas station owners - if you are somewhere in NYC area, you might get some naphtalin added into the mix, as those guys don't give a damn about what EPA or municipal authorities mandate.