Recommended Fuel; Gasoline Specifications; California Fuel; Requirements - GMC 2013 Yukon XL Denali Owner's Manual

Vehicles that have a yellow fuel cap
can use either unleaded gasoline or
ethanol fuel containing up to 85%
ethanol (E85). See
. For all other
vehicles, use only the unleaded
gasoline described under

Recommended Fuel

Use premium unleaded gasoline
with a posted octane rating of 91 or
higher. You can also use regular
unleaded gasoline rated at
87 octane or higher, but the
vehicle's acceleration could be
slightly reduced, and a slight audible
knocking noise, commonly referred
to as spark knock, might be heard.
If the octane is less than 87, you
might notice a heavy knocking noise
when you drive. If this occurs, use a
gasoline rated at 87 octane or
higher as soon as possible.
Otherwise, you could damage the
engine. If heavy knocking is heard
when using gasoline rated at
91 octane or higher, the engine
needs service.

Gasoline Specifications

At a minimum, gasoline should meet
ASTM specification D 4814. Some
gasolines contain an
.
octane-enhancing additive called
methylcyclopentadienyl manganese
tricarbonyl (MMT). We recommend
against the use of gasolines
containing MMT. See
.
Driving and Operating

California Fuel

Requirements

If the vehicle is certified to meet
California Emissions Standards, it is
designed to operate on fuels that
meet California specifications. See
the underhood emission control
label. If this fuel is not available in
states adopting California Emissions
Standards, the vehicle will operate
satisfactorily on fuels meeting
federal specifications, but emission
control system performance might
be affected. The malfunction
indicator lamp could turn on and the
vehicle might fail a smog check test.
See
. If this occurs, return to
your authorized dealer for diagnosis.
If it is determined that the condition
is caused by the type of fuel used,
repairs might not be covered by the
vehicle warranty.
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