Fuel E85 (85% Ethanol) - GMC Yukon Owner's Manual

Some gasolines that are not reformulated for low
emissions can contain an octane-enhancing additive
called methylcyclopentadienyl manganese tricarbonyl
(MMT); ask the attendant where you buy gasoline
whether the fuel contains MMT. We recommend against
the use of such gasolines. Fuels containing MMT can
reduce the life of spark plugs and the performance
of the emission control system could be affected.
The malfunction indicator lamp might turn on. If this
occurs, return to your dealer for service.

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 6 117.
If the vehicle has the 5.3L V8 engine (Code 0), the
5.3L V8 engine (VIN Code 3), the 6.0L V8 engine
(VIN Code J), or the 6.2L V8 engine (Code 2), you can
use either unleaded gasoline or ethanol fuel containing
up to 85% ethanol (E85). See Fuel on page 6 6.
In all other engines, use only the unleaded gasoline
described under Gasoline Octane on page 6 7.
Only vehicles that have the 5.3L V8 engine (Code 0),
the 5.3L V8 engine (VIN Code 3), the 6.0L V8 engine
(VIN Code J), or the 6.2L V8 engine (Code 2) 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.
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