Hello X-Air Owners, Here is some information with regards to Ethanol mix fuels in Fuel tanks of the X-Air range of aircraft including the Standard, Flap model and Hanuman. X-Air aircraft are equipped with Fiberglass fuel tanks. These are not suitable for storing Ethanol based fuels. NOTE: No X-Air aircraft fuel tank is equipped to take ethanol mix fuels. We recommend sealing your tank with the following product. http://www.kreemproducts.net/p-16-kreem-tank-prep.aspx Once the tank is sealed it will resist to the Ethanol. You may also need to change your fuel lines to the correct type. hope the above is clear kind regards Vrata ----------------------------------------------------- Raj Hamsa Ultralights Pvt Ltd 40 Goshala Rd Garudacharpalya Mahadevpura P.O., Bangalore, 560 048 South India Tel:+91(0)80-28516937 Fax: +91(0)80-28518485 URL: www.x-air.in ---------------------------------------------------------