2009 GMC Savana Van Owner's Manual - Page 250

Fuel E85 (85% Ethanol) The 8th digit of the Vehicle Identification Number (VIN) shows the code letter or number that identifies the vehicle's engine. The VIN is at the top left of the instrument panel. See Vehicle Identification Number (VIN) on page 5-103. If the vehicle has the 5.3L V8 engine (VIN Code 4) and the N15 flexible fuel option, you can use either unleaded gasoline or ethanol fuel containing up to 85% ethanol (E85). See Fuel on page 5-5. For the 5.3L V8 engine (VIN Code 4) without the N15 option and all other gasoline engines, use only the unleaded gasoline described under Gasoline Octane on page 5-6. Only vehicles that have the 5.3L V8 engine (VIN Code 4) and the N15 flexible fuel option can use 85% ethanol fuel (E85). We encourage the use of E85 in vehicles that are designed to use it. The ethanol in E85 is a "renewable" fuel, meaning it is made from renewable sources such as corn and other crops. Many service stations will not have an 85% ethanol fuel (E85) pump available. The U. S. Department of Energy has an alternative fuels website (www.eere.energy.gov/ afdc/infrastructure/locator.html) that can help you find E85 fuel. Those stations that do have E85 should have a label indicating ethanol content. Do not use the fuel if the ethanol content is greater than 85%. At a minimum, E85 should meet ASTM Specification D 5798. By definition, this means that fuel labeled E85 will have an ethanol content between 70% and 85%. Filling the fuel tank with fuel mixtures that do not meet ASTM specifications can affect driveability and could cause the malfunction indicator lamp to come on. To ensure quick starts in the wintertime, the E85 fuel must be formulated properly for your climate according to ASTM specification D 5798. If you have trouble starting on E85, it could be because the E85 fuel is not properly formulated for your climate. If this happens, switching to gasoline or adding gasoline to the fuel tank can improve starting. For good starting and heater efficiency below 32°F (0°C), the fuel mix in the fuel tank should contain no more than 70% ethanol. It is best not to alternate repeatedly between gasoline and E85. 5-8