2008 CADILLAC STS open gas tank

Fuel
Use of the recommended fuel is an important part of the
proper maintenance of your vehicle. To help keep the
engine clean and maintain optimum vehicle
performance, we recommend the use of gasoline
advertised as TOP TIER Detergent Gasoline.
The 8th digit of the Vehicle Identication Number (VIN)
shows the code letter or number that identies your
vehicle’s engine. The VIN is at the top left of the
instrument panel. SeeVehicle Identification Number
(VIN) on page 5-116.
Gasoline Octane
If your vehicle has the 3.6L V6 engine (VIN Code V),
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.If your vehicle has the 4.6L V8 engine (VIN Code A),
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
your 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.
If your vehicle has the 4.4L V8 engine (VIN Code D), use
premium unleaded gasoline with a posted octane rating
of 91 or higher. For best performance, use premium
unleaded gasoline with a posted octane rating of 93. In
an emergency, you can use regular unleaded gasoline
with an octane rating of 87 or higher. If 87 octane fuel is
used, do not perform any aggressive driving maneuvers
such as wide open throttle applications. You might also
hear audible spark knock during acceleration. Rell the
tank with premium fuel as soon as possible to avoid
damaging the engine. If you are using gasoline rated at
91 octane or higher and you hear heavy knocking, the
engine needs service.
5-5

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/retailer for service.
Fuels in Foreign Countries
If you plan on driving in another country outside the
United States or Canada, the proper fuel might be hard
to nd. Never use leaded gasoline or any other fuel
not recommended in the previous text on fuel. Costly
repairs caused by use of improper fuel would not
be covered by your warranty.
To check the fuel availability, ask an auto club, or
contact a major oil company that does business in the
country where you will be driving.
Filling the Tank
{CAUTION:
Fuel vapor burns violently and a fuel re can
cause bad injuries. To help avoid injuries to
you and others, read and follow all the
instructions on the pump island. Turn off your
engine when you are refueling. Do not smoke
if you are near fuel or refueling your vehicle.
Do not use cellular phones. Keep sparks,
ames, and smoking materials away from fuel.
Do not leave the fuel pump unattended when
refueling your vehicle. This is against the law
in some places. Do not re-enter the vehicle
while pumping fuel. Keep children away from
the fuel pump; never let children pump fuel.
5-7

The CHECK GAS CAP message will appear on the
Driver Information Center (DIC) display if the fuel cap is
not reinstalled properly. SeeDIC Warnings and
Messages on page 3-80for 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 3-68.
Filling a Portable Fuel Container
{CAUTION:
Never ll a portable fuel container while it is in
your vehicle. Static electricity discharge from
the container can ignite the fuel vapor. You
can be badly burned and your vehicle
damaged if this occurs. To help avoid injury to
you and others:
Dispense fuel only into approved
containers.
Do not ll a container while it is inside a
vehicle, in a vehicle’s trunk, pickup bed, or
on any surface other than the ground.
Bring the ll nozzle in contact with the
inside of the ll opening before operating
the nozzle. Contact should be maintained
until the lling is complete.
Do not smoke while pumping fuel.
Do not use a cellular phone while
pumping fuel.
5-9

Engine (cont.)
Enhanced StabiliTrak®....................................... 4-9
Entry Lighting.................................................3-41
Event Data Recorders.....................................7-16
Extender, Safety Belt.......................................1-27
Exterior Lighting Battery Saver..........................3-40
F
Filter
Engine Air Cleaner......................................5-23
Finish Damage.............................................5-114
Flashers, Hazard Warning.................................. 3-6
Flash-to-Pass.................................................3-13
Flat Tire........................................................5-86
Flat Tire, Changing.........................................5-96
Flat Tire, Storing...........................................5-104
Fluid.............................................................5-25
Power Steering...........................................5-39
Windshield Washer......................................5-40
Fog Lamp
Fog ...........................................................3-39
Fog Lamp Light..............................................3-72
Forward Collision Alert (FAC) System................3-10
Front Axle......................................................5-52
Fuel............................................................... 5-5
Additives...................................................... 5-6
California Fuel.............................................. 5-6Fuel (cont.)
Filling a Portable Fuel Container..................... 5-9
Filling the Tank............................................. 5-7
Fuels in Foreign Countries.............................. 5-7
Gage.........................................................3-73
Gasoline Octane........................................... 5-5
Gasoline Specications.................................. 5-6
Fuses
Fuses and Circuit Breakers.........................5-117
Rear Underseat Fuse Block.........................5-121
Underhood Fuse Block...............................5-118
Windshield Wiper.......................................5-117
G
Gage
Engine Coolant Temperature.........................3-67
Fuel..........................................................3-73
Speedometer..............................................3-59
Tachometer.................................................3-59
Garage Door Opener.......................................2-51
Gasoline
Octane........................................................ 5-5
Specications............................................... 5-6
Glove Box.....................................................2-58
GM Mobility Reimbursement Program.................. 7-6
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