Fuel E-85 (85% Ethanol) - Chevrolet 2005 Silverado 1500 Pickup Owner's Manual

Fuel E-85 (85% Ethanol)

The 8th digit of your vehicle identification number (VIN)
shows the code letter or number that identifies your
engine. You will find the VIN at the top left of the
instrument panel. See Vehicle Identification
Number (VIN) on page 5-126.
If your vehicle has the 5.3L V8 engine (VIN Code Z
only), you may use either regular unleaded gasoline or
ethanol fuel containing up to 85% ethanol (E-85);
also see Fuel on page 5-5. In all other engines, including
the 5.3L V8 (VIN Code T), use only regular unleaded
gasoline.
Only vehicles that have the 5.3L V8 engine (VIN
Code Z) may use 85% ethanol fuel (E-85). General
Motors encourages the use of E-85 in vehicles that are
designed to use it. The ethanol in E-85 is a "renewable"
fuel, meaning it is made from renewable sources
such as corn and other crops.
5-8
Many service stations will not have an 85% ethanol
fuel (E-85) pump available. The U. S. Department
of Energy has an alternative fuels website
(http://www.afdc.doe.gov/refueling_mapsite.shtml) that
can help you find E-85 fuel. Those stations that do have
E-85 should have a label indicating ethanol content.
Do not use the fuel if the ethanol content is greater than
85%. Your vehicle may not operate properly if the
ethanol content is greater than 85%.
At a minimum, E-85 should meet ASTM
Specification D 5798.
To ensure 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 (0°C), the fuel mix in the fuel tank should
contain no more than 70% ethanol.