Buick 2010 Lucerne - Manual (Page 310)

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 6‑109.
If the vehicle has the 3.9L V6 engine (VIN Code M), you
can use either unleaded gasoline or ethanol fuel
containing up to 85% ethanol (E85). See Fuel on
page 6‑5. In all other engines, use only the unleaded
gasoline described under Gasoline Octane on
page 6‑6.
Only vehicles that have the 3.9L V6 engine
(VIN Code M) 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 0°C (32°F), 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
11 L (three gallons) when refueling. You should drive
the vehicle immediately after refueling for at least
11 km (seven miles) to allow the vehicle to adapt to the
change in ethanol concentration.
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