GMC 2009 Savana - 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