Fuel E85 (85% Ethanol) - Chevrolet Silverado Classic 2007 Owner's Manual

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 600.
If your vehicle has the 5.3L V8 engine (VIN Code Z
only), you can use either regular unleaded gasoline
or ethanol fuel containing up to 85% ethanol (E85);
also see Fuel on page 470. In all other engines, use
only the unleaded gasoline described under
Gasoline Octane on page 471.
Only vehicles that have the 5.3L V8 engine
(VIN Code Z) 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 check engine light 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. If you do switch fuels, it is recommended that
you add as much fuel as possible — do not add
less than three gallons (11 L) when refueling.
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