2003 Chevrolet Tahoe Owner's Manual - Page 361

At a minimum, E-85 should meet ASTM Specification D 5798. To insure quick starts in the wintertime, the E-85 fuel must be formulated properly for your climate according to ASTM specification D 5798. If you have trouble starting on E-85, it may be because your E-85 fuel is not properly formulated for your climate. If this happens, switching to gasoline or adding gasoline to your fuel tank may improve starting. Your vehicle is designed to accommodate a mixture of gasoline and E-85 fuel. for good starting and heater efficiency below 32°F (OOC), the fuel mix in the fuel tank should contain no more than 70% ethanol. E-85 has less energy per gallon than gasoline, so you'll need to refill your fuel tank more often when using E-85 than when you're using gasoline. Regular unleaded gasoline is recommended when pulling a trailer. For payload capacity with ethanol fuel, see Loading Your Vehicle on page 4-56. Notice: Some additives are not compatible with E-85 fuel and may harm your fuel system. Damage caused by additives wouldn't be covered by your new vehicle warranty. Don't use additives with E-85 fuel. Notice: Your vehicle was not designed for fuel that contains methanol. Don't use fuel containing methanol. It can corrode metal parts in your fuel system and also damage the plastic and rubber parts. That damage wouldn't be covered under your warranty. Fuels in Foreign Countries If you plan on driving in another country outside the United States or Canada, the proper fuel may be hard to find. Never use leaded gasoline or any other fuel not recommended in the previous text on fuel. Costly repairs caused by use of improper fuel wouldn't be covered by your warranty. To check the fuel availability, ask an auto club, or contact a major oil company that does businessin the country where you'll be driving. 5-8