Recommended Fuel; Gasoline Specifications; California Fuel - GMC Yukon Denali 2014 Owner's Manual

9-48 Driving and Operating

Recommended Fuel

Use premium unleaded gasoline
with a posted octane rating of 91 or
higher. Regular unleaded gasoline
rated at 87 octane or higher can be
used, but acceleration could be
reduced, and an audible knocking
noise may be heard. If the octane is
less than 87, a heavy knocking
noise may be heard. If this occurs,
use a gasoline rated at 87 octane or
higher as soon as possible.
Otherwise, the engine could be
damaged. If heavy knocking is
heard when using gasoline with a
higher octane rating, the engine
needs service.
Use of Seasonal Fuels
Use summer and winter fuels in the
appropriate season. Driving or
starting could be affected if the
incorrect fuel is used. Drive the
vehicle with the engine running until
the fuel is a half tank or less, then
refuel with the current seasonal fuel.
Prohibited Fuels
Gasolines containing oxygenates,
such as ethers and ethanol, as well
as reformulated gasolines are
available in some cities. If these
gasolines comply with the
previously described specification,
then they are acceptable to use.
However, E85 and other fuels
containing more than 15% ethanol
must be used only in FlexFuel
vehicles.
Notice: Do not use fuel
containing methanol. It can
corrode metal parts in the fuel
system and also damage plastic
and rubber parts. That damage
would not be covered under the
vehicle warranty.
Some gasolines that are not
reformulated for low emissions can
contain an octane-enhancing
additive called
methylcyclopentadienyl manganese
tricarbonyl (MMT). Do not use
gasolines with MMT as they can
reduce spark plug life and affect
emission control system
performance. The malfunction
indicator lamp may turn on. If this
occurs, see your dealer for 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 Prohibited
Fuels" in Recommended Fuel on
page 9-48.

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