http://gulfracingfuels.com/isobutanol-and-going-ethanolfree/Isobutanol and Going Ethanol Free
Why Gulf Uses Isobutanol:
Some our fuels use an additive called ISOBUTANOL, an advanced biofuel, to replace ethanol. Isobutanol is an EPA Approved oxygenate containing 30% higher BTU than ethanol, while producing power beyond typical ethanol-based gasoline.
ISOBUTANOL is not hygroscopic which means it will not absorb nor accumulate water, nor will the fuels damage or affect gas tanks, gaskets, carburetors or injectors. Our fuels, using ISOBUIANOL, meet all engine makers requirements which means these fuels will not void engine warranties. The National Marine Manufacturers Association has endorsed gasoline containing ISOBUTANOL as being better that using fuels containing ethanol.
Gulf fuels containing ISOBUTANOL are excellent for everyday engines and high performance engines operating is high humidity environments or any environment around water. The fuels can also be used in engines that are used only occasionally as the fuel when static will not absorb water. Racing applications include Hydroplane drag boats, offshore racing boats, high altitude racing and snowmobiles.