Your bike feels "smoother" with 93 octane because it's making less power per combustion stroke, and therefore less vibration.
Unless an engine has high enough compression to NEED octane over 87, running anything higher will result in less power. On the other hand, if your tuning sucks, or you have a ton of carbon built up in the combustion chamber you may have a case where higher octane would be of benefit, but that's a motor problem, not an octane statement.
A motor makes the most power running the LOWEST octane it can without pre-ignition or detonation, period. The only way to get more power from higher octane is to raise compression, advance the timing, use forced induction, etc. Of COURSE a race motor makes more power on race gas, because it has very high compression, more advanced timing, etc. A V-Max engine, OTOH, has compression and timing setup by Yamaha for 87 octane. Unless you increase that compression or advance the timing over stock (assuming it's less than optimum already), more octane = less power.
If (I'm not sure on this one), the V-Max was tuned to be right on the "edge" with 87 octane, i.e. it's "barely enough" then a point or two more would be of benefit; I don't know how close Yamaha tuned it, but usually they are pretty conservative with it, so I doubt it's close. A V-Max motor isn't very high strung or high compression really compared to many motors of today.
As far as quality, most name brand gas around here has the same additives regardless of grade (Chevron and Texaco to name a few use Techron in all grades), so that's a moot point too.
I've hand built quite a few high HP automotive supercharged engines, used to be sponsored by the Vortech supercharger company, tuned EFI all day long for years, the above statements have quite a bit of experience behind them, not just something I "Read on the Internet."
unk:
