Page 258 of 406

If the vehicle has the 5.3L V8 engine (VIN Code C), 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 you might
notice a slight audible knocking noise, commonly referred
to as spark knock. 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 you are using gasoline rated at 87 octane or
higher and you hear heavy knocking, the engine needs
service.
Gasoline Speci cations
At a minimum, gasoline should meet ASTM speci cation
D 4814 in the United States or CAN/CGSB-3.5 or 3.511 in
Canada. Some gasolines contain an octane-enhancing
additive called methylcyclopentadienyl manganese
tricarbonyl (MMT). We recommend against the use of
gasolines containing MMT. SeeAdditives on page 5-6for
additional information.
California Fuel
If the vehicle is certi ed to meet California Emissions
Standards, it is designed to operate on fuels that meet
California speci cations. 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 speci cations, but
emission control system performance might be affected.
The malfunction indicator lamp could turn on and the
vehicle might fail a smog-check test. SeeMalfunction
Indicator Lamp on page 3-36. If this occurs, return to your
authorized dealer/retailer 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.
Additives
To provide cleaner air, all gasolines in the United States
are now required to contain additives that help prevent
engine and fuel system deposits from forming, allowing
the emission control system to work properly. In most
cases, you should not have to add anything to the fuel.
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        Page 263 of 406

{CAUTION:
Fuel can spray out on you if you open the fuel cap
too quickly. If you spill fuel and then something
ignites it, you could be badly burned. This spray
can happen if the tank is nearly full, and is more
likely in hot weather. Open the fuel cap slowly and
wait for any hiss noise to stop. Then unscrew the
cap all the way.
Be careful not to spill fuel. Do not top off or over ll the
tank and wait a few seconds after you have  nished
pumping before removing the nozzle. Clean fuel from
painted surfaces as soon as possible. SeeWashing Your
Vehicle on page 5-92.
When replacing the fuel cap, turn it clockwise until it
clicks. Make sure the cap is fully installed. The diagnostic
system can determine if the fuel cap has been left off or
improperly installed. This would allow fuel to evaporate
into the atmosphere. SeeMalfunction Indicator Lamp on
page 3-36.The TIGHTEN GAS CAP message displays on the Driver
Information Center (DIC) if the fuel cap is not properly
installed. SeeDIC Warnings and Messages on page 3-49
for more information.
{CAUTION:
If a  re starts while you are refueling, do not
remove the nozzle. Shut off the  ow of fuel by
shutting off the pump or by notifying the station
attendant. Leave the area immediately.
Notice:If you need a new fuel cap, be sure to get the
right type. Your dealer/retailer can get one for you. If
you get the wrong type, it may not  t properly. This
may cause the malfunction indicator lamp to light
and may damage the fuel tank and emissions system.
SeeMalfunction Indicator Lamp on page 3-36.
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        Page 390 of 406

Vehicle Data Recording and
Privacy
Your GM vehicle has a number of sophisticated
computers that record information about the vehicle’s
performance and how it is driven. For example, your
vehicle uses computer modules to monitor and control
engine and transmission performance, to monitor the
conditions for airbag deployment and deploy airbags
in a crash and, if so equipped, to provide antilock braking
to help the driver control the vehicle. These modules
may store data to help your dealer/retailer technician
service your vehicle. Some modules may also store data
about how you operate the vehicle, such as rate of fuel
consumption or average speed. These modules may also
retain the owner’s personal preferences, such as radio
pre-sets, seat positions, and temperature settings.
Event Data Recorders
This vehicle has an Event Data Recorder (EDR).
The main purpose of an EDR is to record, in certain
crash or near crash-like situations, such as an airbag
deployment or hitting a road obstacle, data that will assist
in understanding how a vehicle’s systems performed.
The EDR is designed to record data related to vehicle
dynamics and safety systems for a short period of time,
typically 30 seconds or less. The EDR in this vehicle is
designed to record such data as:
How various systems in your vehicle were operating
Whether or not the driver and passenger safety belts
were buckled/fastened
How far, if at all, the driver was pressing the
accelerator and/or brake pedal
How fast the vehicle was traveling
This data can help provide a better understanding of the
circumstances in which crashes and injuries occur.
Important:EDR data is recorded by your vehicle
only if a non-trivial crash situation occurs; no data is
recorded by the EDR under normal driving conditions
and no personal data (e.g., name, gender, age, and crash
location) is recorded. However, other parties, such as law
enforcement, could combine the EDR data with the type
of personally identifying data routinely acquired during a
crash investigation.
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