Page 164 of 331

4-32
Maximum trailer weight is calculated by subtracting 
the weight of your completed vehicle from the GCWR. 
The weight of the completed vehicle, passengers, cargo
in the tow vehicle and the loaded trailer weight must not
exceed the GCWR.
Refer to the Trailering Guide for oil cooler
recommendations.
EngineAxle
RatioGross Combination 
Weight Rating
6.5L Diesel 4.63 17,000 lbs. (7 718 kg)
5.13 17,000 lbs. (7 718 kg)
8.1L 4.63 19,000 lbs. (8 626 kg)
5.13 19,000 lbs. (8 626 kg)
You can ask your dealer for our trailering information or
advice, or you can write us at the address listed in your
Warranty and Owner Assistance Information Booklet.
In Canada, write to:
General Motors of Canada Limited
Customer Communication Centre, 163
-005
1908 Colonel Sam Drive
Oshawa, Ontario L1H 8P7
Weight of the Trailer Tongue
The tongue load (A) of any trailer is an important
weight to measure because it affects the total or gross
weight of your vehicle. The Gross Vehicle Weight
(GVW) includes the curb weight of the vehicle, any
cargo you may carry in it, and the people who will be
riding in the vehicle. And if you will tow a trailer, you
must add the tongue load to the GVW because your
vehicle will be carrying that weight, too. See ªLoading
Your Vehicleº in the Index for more information about
your vehicle's maximum load capacity. 
     
        
        Page 206 of 331

6-11
Engine Oil (Gasoline Engine)
If your vehicle has a diesel engine, see ªEngine Oil
(Diesel Engine)º in the Diesel Engine Supplement.
Checking Engine Oil
It's a good idea to check your engine oil every time you
get fuel. In order to get an accurate reading, the oil must
be warm and the vehicle must be on level ground.
The engine oil dipstick 
has a yellow ring handle
and is located in the 
engine compartment on 
the passenger's side of 
the vehicle. See ªEngine
Compartment Overviewº 
in the Index for more
information on location.
Turn off the engine and give the oil several minutes to
drain back into the oil pan. If you don't, the oil dipstick
might not show the actual level.Pull out the dipstick and clean it with a paper towel or
cloth, then push it back in all the way. Remove it again,
keeping the tip down, and check the level.
When to Add Engine Oil
If the oil is at or below the ADD mark, then you'll need
to add at least one quart of oil. But you must use the
right kind. This part explains what kind of oil to use. 
For engine oil crankcase capacity, see ªCapacities and
Specificationsº in the Index. 
     
        
        Page 262 of 331
6-67 Capacities
After refill, the level must be rechecked. See ªCooling
Systemº in the Index.
 Engine  VIN Quantity
ªVORTECº 8100 G 28.5 quarts (27.0 L)
Engine Oil with Filter
After refill, the level must be rechecked. Add enough
engine oil so that the fluid is within the proper operating
range. See ªEngine Oilº in the Index.
 Engine VIN Quantity
ªVORTECº 8100 G 6.6 quarts (6.3 L)
Fuel Tank Capacity
Type Quantity
Front Tank 22.0 U.S. gallons (79 L)
Rear Tank 18.0 U.S. gallons (68 L)
Air Conditioning 
Refrigerant Capacity
If you do your own service work, you'll need the proper
service manual. See ªDoing Your Own Service Workº in
the Index for additional information. It is recommended
that service work on your air conditioning system be
performed by a qualified technician.
Air Conditioning 
Refrigerant R
-134a 2.0 lbs (0.91kg). . . . . . . . . . . . . 
Use Refrigerant Oil, R134a Systems 
     
        
        Page 263 of 331

6-68
Normal Maintenance 
Replacement Parts
Replacement part numbers listed in this section are
based on the latest information available at the time of
printing, and are subject to change. If a part listed in 
this manual is not the same as the part used in your
vehicle when it was built, or if you have any questions,
please contact your GM truck dealer.
These specifications are for information only. If you
have any questions, see the service manual for the
chassis or refer to the body manufacturer's publications.VIN Code G. . . . . . . . . . . . . . . . . . . . . . . . . . . . 
Oil Filter* PF454. . . . . . . . . . . . . . . . . . . . . . . . 
Engine Air Cleaner Filter* A1300C . . . . . . . . 
Spark Plugs*** TJ14R-P15 . . . . . . . . . . . . . . . 
Fuel Filter* GF626. . . . . . . . . . . . . . . . . . . . . . . 
Wiper Blades** 22154886. . . . . . . . . . . . . . . . . 
Wiper Blade Type Trico. . . . . . . . . . . . . . . . . . 
Wiper Blade Length 18 inches (45.0 cm). . . . . . 
*ACDelco
 part number
**GM part number
***Denso part number
A1301C high
-capacity air cleaner filter.