Heard arguments in both directions. Some guys have reported that higher octaine actually caused problems, so they went back to the lower octaine. The argument there is that with all the addatives and specific formulation our "modern" gas has these days, it doesn't last that long. I've read somewhere that more than 60 days in the dealer's tank and it starts to break down. And, since a lot less people actually buy the expensive stuff, it's much more likely that you are putting older gas in your bike. Therefore, the spitting, sputtering, and the like. These same guys then switch to lower octaine, which happens to be fresher beacuse the dealer's tank is getting filled up much more often, and the problem goes away. I happen to live in a part of Tucson where there are a lot of high end sports cars and bikes, so I think our higher octaine stuff may be a bit fresher (refilled more often) as I've never had that problem. But, if you live in a smaller town, or an area with a population that doens't go for much of the good stuff, then it is possible you are actaully doing your bike a disservice by going for stale high octaine. It might be worth aksing the attendant or manager where you fill up just how often they get your favoite blend reflilled at that particular station.