1995 Chevrolet Corvette Owner's Manual - Page 238

Be sure the posted octane is at least 91. If the octaneis less than 91, you may get a heavy knocking noise when you drive. (In an emergency, you may be able to use lower octane -- as low as 87 -- if heavy knocking does unleaded not occur.) If you're using 91 or higher octane gas and you still get heavy knocking, your engine needs service. What about gasoline with blending materials that contain oxygen (oxygenates), such as MTBE or alcohol? iWethanol is methyl or wood alcohol. NOTICE: Fuel that is more than 5 % methanol is bad for your vehicle. Don't use it. can corrode metal It parts in your fuel systemand also damage plastic and rubberparts. That damage wouldn't be covered under your warranty. And even at 5 % or less, there must be "cosolvents"and corrosion preventers in this fuel to help avoidthese problems. MTBE is "methyl tertiary-butyl ether." Fuel that is no more than 15% MTBE is fine foryour vehicle. Ethanol is ethyl or grain alcohol. Properly-blended fuel that is no more than 10% ethanol is fine foryour vehicle. 6-3