fuel type GMC ENVOY DENALI 2008 Owners Manual

Gasoline Octane
Use regular unleaded gasoline with a posted octane
rating of 87 or higher. If the octane rating is less than 87,
you might notice an audible knocking noise when you
drive, commonly referred to as spark knock. If this
occurs, use a gasoline rated at 87 octane or higher as
soon as possible. If you are using gasoline rated at
87 octane or higher and you hear heavy knocking, the
engine needs service.
Gasoline Specications
At a minimum, gasoline should meet ASTM specication
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 5-7for
additional information.
California Fuel
If your vehicle is certied to meet California Emissions
Standards, it is designed to operate on fuels that meet
California specications. See the underhood emission
control label. If this fuel is not available in states adopting
California emissions standards, your vehicle will operate
satisfactorily on fuels meeting federal specications, but
emission control system performance might be affected.
The malfunction indicator lamp could turn on and your
vehicle might fail a smog-check test. SeeMalfunction
Indicator Lamp on page 3-41. 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 your warranty.
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{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 your 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 overll 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 5-103.
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 3-41.There may also be a light that comes on in the
instrument panel to let you know if your gas cap is not
properly installed. SeeCheck Gas Cap Light on
page 3-49for 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 your malfunction indicator
lamp to light and may damage your fuel tank and
emissions system. SeeMalfunction Indicator Lamp
on page 3-41.
5-9

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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