2002 GMC SONOMA octane

4-54
4WD Extended Cab
4.3L V6/Manual Trans. 3.42 4,000 lbs. (1 816 kg)
4.3L V6/Manual Trans. w/ZR2 3.73 4,200 lbs. (1 907 kg)
4.3L V6/Auto. Trans. 3.42 5,500 lbs. (2 497 kg)
3.73 5,500 lbs. (2 497 kg)
4.3L V6/Auto. Trans. w/ZR2 3.73 5,500 lbs. (2 497 kg)
4WD Crew Cab
4.3L V6/Auto. Trans. 3.42 5,200 lbs. (2 361 kg)
3.73 5,200 lbs. (2 361 kg)
* If your vehicle is equipped with RPO V4A (Xtreme
Sport Appearance Package), your vehicle was neither
intended nor designed to tow a trailer. For more information on RPO codes, see ªService Parts Identification Labelº
in the Index.
#If your vehicle is equipped with a code 5 engine you must use regular unleaded gasoline rated at 87 octane or higher
when towing.
Maximum trailer weight is calculated assuming the driver and one passenger are in the tow vehicle and it has all the
required trailering equipment. The weight of additional optional equipment, passengers and cargo in the tow vehicle
must be subtracted from the maximum trailer weight. The weight of the trailer tongue also affects trailering capacity.
See ªWeight of the Trailer Tongueº later in this section.
**The Gross Combination Weight Rating (GCWR) is the total allowable weight of the completely loaded vehicle and
trailer including any passengers, cargo, equipment and conversions. The GCWR for your vehicle should not be
exceeded.

6-3
CAUTION:
You can be injured and your vehicle could be
damaged if you try to do service work on a
vehicle without knowing enough about it.

Be sure you have sufficient knowledge,
experience, the proper replacement parts
and tools before you attempt any vehicle
maintenance task.

Be sure to use the proper nuts, bolts and
other fasteners. ªEnglishº and ªmetricº
fasteners can be easily confused. If you use
the wrong fasteners, parts can later break
or fall off. You could be hurt.
Adding Equipment to the Outside of
Your Vehicle
Things you might add to the outside of your vehicle can
affect the airflow around it. This may cause wind noise
and affect windshield washer performance. Check with
your dealer before adding equipment to the outside of
your vehicle.
Fuel (Gasoline)
The 8th digit of your vehicle identification number
(VIN) shows the code letter or number that identifies
your engine. You will find the VIN at the top left of the
instrument panel. See ªVehicle Identification Numberº
in the Index.
If your vehicle has the 2200 L4 engine (VIN Code 5),
you may use either regular unleaded gasoline or ethanol
fuel containing up to 85% ethanol (E
-85); also see
ªFuel E
-85 (85% Ethanol)º following. If your
vehicle has the 4.3L V6 engine, use only regular
unleaded gasoline.
Gasoline Octane
Use regular unleaded gasoline with a posted octane of
87 or higher. If the octane is less than 87, you may
get a heavy knocking noise when you drive. If it is bad
enough, it can damage your engine. A little pinging
noise when you accelerate or drive uphill is considered
normal. This does not indicate a problem exists or that
a higher
-octane fuel is necessary.

6-4 Gasoline Specifications
It is recommended that gasoline meet specifications
which were developed by the American Automobile
Manufacturers Association and endorsed by the
Canadian Vehicle Manufacturers' Association for better
vehicle performance and engine protection. Gasolines
meeting these specifications could provide improved
driveability and emission control system performance
compared to other gasolines.
In Canada, look for
the ªAuto Makers'
Choiceº label on
the pump.
Canada Only
California Fuel
If your vehicle is certified to meet California Emission
Standards (see the underhood emission control label), it
is designed to operate on fuels that meet California
specifications. If this fuel is not available in states
adopting California emissions standards, your vehicle
will operate satisfactorily on fuels meeting federal
specifications, but emission control system performance
may be affected. The malfunction indicator lamp may
turn on (see ªMalfunction Indicator Lampº in the Index)
and your vehicle may fail a smog
-check test. If this
occurs, return to your authorized GM dealer for
diagnosis. If it is determined that the condition is caused
by the type of fuel used, repairs may not be covered by
your warranty.
Additives
Some gasolines that are not reformulated for low
emissions may contain an octane
-enhancing additive
called methylcyclopentadienyl manganese tricarbonyl
(MMT); ask the attendant where you buy gasoline
whether the fuel contains MMT. General Motors
does not recommend the use of such gasolines.