2008 Chevrolet Tahoe Owner's Manual - Page 371

Fuel E85 (85% Ethanol) The 8th digit of the Vehicle Identification Number (VIN) shows the code letter or number that identifies your vehicle's engine. The VIN is at the top left of the instrument panel. See Vehicle Identification Number (VIN) on page 5-115. If your vehicle has the 5.3L V8 engine (Code 0) or the 5.3L V8 engine (Code 3), you can use either regular unleaded gasoline or ethanol fuel containing up to 85% ethanol (E85); also see Fuel on page 5-5. In all other engines, use only the unleaded gasoline described under Gasoline Octane on page 5-5. Only vehicles that have the 5.3L V8 engine (Code 0) or the 5.3L V8 engine (Code 3) 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 drivability and could cause the malfunction indicator lamp to come on. 5-7