[toneman]

snoman--please don't get me wrong; I hear ya when it comes to using higher octane fuel to take advantage of modified tuning tables or reduction/elimination of knocking/pinging, or if it required for ideal/optimum operation. However...there have been studies (I can't recall the exact source, but trust me on this) where the use of 89 or 91 octane gas in a perfectly-running unmodified car tuned to run on 87 octane--even those with "modern" engines with "high" compression ratios (there seems to be a difference of opinion here as to what value a compression ratio is considered "high") did not show any significant noticeable improvement in fuel economy or performance. Heck, I'm willing to bet that if I put 91 octane in my all-stock YXL, I won't see any noticeable improvement in fuel economy nor will I gain more than a tenth of a second--if at all--in the quarter-mile. And since I'm not getting any knocking or pinging to begin with (other than the CSK that happens every once in a while during cold startups), using higher octane in my truck won't change a thing in the knock/ping departgment.

So...why should I be using 89 or 91 octane instead of 87 in my stock YXL if the above is true?