Woohoo. Contentious issue alert. At the risk of starting a new oil thread:So if understand all the post on the gasoline - i need to use an ethanol free gas ?
According to Suzuki, up to 10% ethanol is not an issue. Your whole fuel system is ethanol-proof. The only real thing is that ethanol contains slightly less energy per cc, so performance of the bike will be marginally down. Whether you'll notice that... I don't think so.
However, ethanol is kind of a magnet for water. When your bike sits too long with a tank half full, water from condensation could work its way into the tank and cause corrosion there. Which eventually could lead to a clogged pump, clogged injectors, leaking tanks and other misery.
So opinions vary. If you're in a moist climate and regularly do not ride the bike for months (winter) then it's probably a good idea to use a tank or two of ethanol-free fuel just before winter starts. If you are in a dry climate and ride regularly, up to 10% ethanol should not be an issue at all.