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CAUTION! (Continued)• When replacing a flat, the spare tire may have to
be remounted on the rim or installed at a different
location to maintain the correct placement of the
tire on the wheel relative to the tire/wheel position
on the vehicle. For example, if the spare is used to
replace an outer rear tire it will have to be re-
mounted on the rim so that the wheel is dished
inward. That way the tread design of asymmetrical
tires will maintain proper position.
FUEL REQUIREMENTS
The 5.7L engine is designed to meet all
emissions regulations and provide satisfac-
tory fuel economy and performance when
using high-quality unleaded gasoline hav-
ing an octane range of 87 to 89. The manu-
facturer recommends the use of 89 octane for optimum performance. The use of premium gasoline
is not recommended, as it will not provide any benefit
over regular gasoline in these engines.
Light spark knock at low engine speeds is not harmful to
your engine. However, continued heavy spark knock at
high speeds can cause damage and immediate service is
required.
Poor quality gasoline can cause problems such as hard
starting, stalling and hesitations. If you experience these
symptoms, try another brand of “regular” gasoline be-
fore considering service for the vehicle.
Over 40 auto manufacturers worldwide have issued and
endorsed consistent gasoline specifications (the World-
wide Fuel Charter, WWFC) to define fuel properties
necessary to deliver enhanced emissions, performance
and durability for your vehicle. We recommend the use
of gasolines that meet the WWFC specifications if they
are available. 5 STARTING AND OPERATING 335
Page 344 of 502

VEHICLE LOADING
Certification Label
As required by National Highway Traffic Safety Admin-
istration regulations, your vehicle has a certification label
affixed to the driver’s side door or pillar.
This label contains the month and year of manufacture,
Gross Vehicle Weight Rating (GVWR), Gross Axle Weight
Rating (GAWR) front and rear, and Vehicle Identification
Number (VIN). A Month-Day-Hour (MDH) number is
included on this label and indicates the Month, Day and
Hour of manufacture. The bar code that appears on the
bottom of the label is your Vehicle Identification Number
(VIN).
Gross Vehicle Weight Rating (GVWR)
The GVWR is the total permissible weight of your vehicle
including driver, passengers, vehicle, options and cargo.
The label also specifies maximum capacities of front and rear axle systems (GAWR). Total load must be limited so
GVWR and front and rear GAWR are not exceeded.
Payload
The payload of a vehicle is defined as the allowable load
weight a truck can carry, including the weight of the
driver, all passengers, options and cargo.
Gross Axle Weight Rating (GAWR)
The GAWR is the maximum permissible load on the front
and rear axles. The load must be distributed in the cargo
area so that the GAWR of each axle is not exceeded.
Each axle GAWR is determined by the components in the
system with the lowest load carrying capacity (axle,
springs, tires or wheels). Heavier axles or suspension
components sometimes specified by purchasers for in-
creased durability does not necessarily increase the vehi-
cle’s GVWR.342 STARTING AND OPERATING
Page 345 of 502

Tire Size
The tire size on the Label represents the actual tire size on
your vehicle. Replacement tires must be equal to the load
capacity of this tire size.
Rim Size
This is the rim size that is appropriate for the tire size
listed.
Inflation Pressure
This is the cold tire inflation pressure for your vehicle for
all loading conditions up to full GAWR.
Curb Weight
The curb weight of a vehicle is defined as the total weight
of the vehicle with all fluids, including vehicle fuel, at full
capacity conditions, and with no occupants or cargo
loaded into the vehicle. The front and rear curb weight
values are determined by weighing your vehicle on a
commercial scale before any occupants or cargo are
added. Loading
The actual total weight and the weight of the front and
rear of your vehicle at the ground can best be determined
by weighing it when it is loaded and ready for operation.
The entire vehicle should first be weighed on a commer-
cial scale to insure that the GVWR has not been exceeded.
The weight on the front and rear of the vehicle should
then be determined separately to be sure that the load is
properly distributed over front and rear axle. Weighing
the vehicle may show that the GAWR of either the front
or rear axles has been exceeded but the total load is
within the specified GVWR. If so, weight must be shifted
from front to rear or rear to front as appropriate until the
specified weight limitations are met. Store the heavier
items down low and be sure that the weight is distributed
equally. Stow all loose items securely before driving.
5 STARTING AND OPERATING 343
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Towing Requirements
To promote proper break-in of your new vehicle drive-
train components the following guidelines are recom-
mended:
CAUTION!• Do not tow a trailer at all during the first 500 miles
(805 km) the new vehicle is driven. The engine,
axle or other parts could be damaged.
• Then, during the first 500 miles (805 km) that a
trailer is towed, do not drive over 50 mph
(80 km/h) and do not make starts at full throttle.
This helps the engine and other parts of the
vehicle wear in at the heavier loads. WARNING!Improper towing can lead to a collision. Follow these
guidelines to make your trailer towing as safe as
possible:
• Make certain that the load is secured in the trailer
and will not shift during travel. When trailering
cargo that is not fully secured, dynamic load shifts
can occur that may be difficult for the driver to
control. You could lose control of your vehicle and
have a collision.
• When hauling cargo or towing a trailer, do not
overload your vehicle or trailer. Overloading can
cause a loss of control, poor performance or dam-
age to brakes, axle, engine, transmission, steering,
suspension, chassis structure or tires.
(Continued)
5 STARTING AND OPERATING 351
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WARNING! (Continued)• Safety chains must always be used between your
vehicle and trailer. Always connect the chains to
the hook retainers of the vehicle hitch. Cross the
chains under the trailer tongue and allow enough
slack for turning corners.
• Vehicles with trailers should not be parked on a
grade. When parking, apply the parking brake on
the tow vehicle. Put the tow vehicle transmission
in PARK. For four-wheel drive vehicles, make sure
the transfer case is not in NEUTRAL. Always,
block or chock the trailer wheels.
• GCWR must not be exceeded.
• Total weight must be distributed between the tow
vehicle and the trailer such that the following four
ratings are not exceeded:
1. GVWR
(Continued) WARNING! (Continued)2. GTW
3. GAWR
4. Trailer tongue weight rating for the trailer hitch
utilized (This requirement may limit the ability to
always achieve the 10% to 15% range of tongue
weight as a percentage of total trailer weight).
Towing Requirements – Tires
• Do not attempt to tow a trailer with less than the full
size spare tire.
• Proper tire inflation pressures are essential to the safe
and satisfactory operation of your vehicle. Refer to
“Tires – General Information” in “Starting and Oper-
ating” for proper tire inflation procedures.
• Check the trailer tires for proper tire inflation pres-
sures before trailer usage.352 STARTING AND OPERATING
Page 355 of 502

• Check for signs of tire wear or visible tire damage
before towing a trailer. Refer to “Tires – General
Information” in “Starting and Operating” for the
proper inspection procedure.
• When replacing tires, refer to “Tires – General Infor-
mation” in “Starting and Operating” for proper tire
replacement procedures. Replacing tires with a higher
load carrying capacity will not increase the vehicle’s
GVWR and GAWR limits.
Towing Requirements – Trailer Brakes
• Do not interconnect the hydraulic brake system or
vacuum system of your vehicle with that of the trailer.
This could cause inadequate braking and possible
personal injury. • An electronically actuated trailer brake controller is
required when towing a trailer with electronically
actuated brakes. When towing a trailer equipped with
a hydraulic surge actuated brake system, an electronic
brake controller is not required.
• Trailer brakes are recommended for trailers over
1,000 lbs (454 kg) and required for trailers in excess of
2,000 lbs (907 kg).
CAUTION!If the trailer weighs more than 1,000 lbs (454 kg)
loaded, it should have its own brakes and they
should be of adequate capacity. Failure to do this
could lead to accelerated brake lining wear, higher
brake pedal effort, and longer stopping distances.
5 STARTING AND OPERATING 353
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6. Press the SELECT button and then press the UP or
DOWN buttons until the proper Trailer Brake Type
appears on the screen.
7. Use the GAIN adjustment (+/-) buttons to increase or
decrease the GAIN setting to the desired starting point. A
GAIN setting of 5 is a good starting point. 8. In a traffic-free environment, tow the trailer on a dry,
level surface at a speed of 20–25 mph (30–40 km/h) and
squeeze the manual brake control lever completely.
9. If the trailer wheels lockup (indicated by squealing
tires), reduce the GAIN setting; if the trailer wheels turn
freely, increase the GAIN setting.
Repeat Steps 8 and 9 until the GAIN setting is at a point
just below trailer wheel lockup. If towing a heavier
trailer, trailer wheel lockup may not be attainable even
with the maximum GAIN setting of 10.
EVIC Display Messages
The trailer brake control interacts with the Electronic
Vehicle Information Center (EVIC). Display messages,
along with a single chime, will be displayed when a
malfunction is determined in the trailer connection,
trailer brake control, or on the trailer. Refer to “Electronic
Vehicle Information Center” in “Understanding Your
Instrument Panel” for further information.358 STARTING AND OPERATING
Page 379 of 502
WARNING! (Continued)• The jack is designed to use as a tool for changing
tires only. The jack should not be used to lift the
vehicle for service purposes. The vehicle should
be jacked on a firm level surface only. Avoid ice or
slippery areas.
3500 Models — If Equipped
The jack and jack tools are stored under the front
passenger seat. Lift the flap on the side of the seat for
access.
Remove the jack and tools by removing the wing bolt and
sliding the assembly from under the seat. Jack Location
6 WHAT TO DO IN EMERGENCIES 377