
Tread Wear Indicators
Tread wear indicators are in the original equipment tires to
help you in determining when your tires should be replaced.
These indicators are molded into the bottom of the tread
grooves. They will appear as bands when the tread depth
becomes a 1/16 of an inch (1.6 mm). When the tread is
worn to the tread wear indicators, the tire should be
replaced. Refer to “Replacement Tires” in this section for
further information.
Life Of Tire
The service life of a tire is dependent upon varying
factors including, but not limited to:
•Driving style.
• Tire pressure - Improper cold tire inflation pressures
can cause uneven wear patterns to develop across the
tire tread. These abnormal wear patterns will reduce
tread life, resulting in the need for earlier tire replace-
ment.
• Distance driven.
Tire Tread
1—WornTire
2—NewTire 546 STARTING AND OPERATING

•Performance tires, tires with a speed rating of V or
higher, and Summer tires typically have a reduced
tread life. Rotation of these tires per the vehicle main-
tenance schedule is highly recommended.
WARNING!
Tires and the spare tire should be replaced after six
years, regardless of the remaining tread. Failure to
follow this warning can result in sudden tire failure.
You could lose control and have a collision resulting
in serious injury or death.
Keep dismounted tires in a cool, dry place with as little
exposure to light as possible. Protect tires from contact
with oil, grease, and gasoline.
Replacement Tires
The tires on your new vehicle provide a balance of many
characteristics. They should be inspected regularly for
wear and correct cold tire inflation pressures. The manu-
facturer strongly recommends that you use tires equiva-
lent to the originals in size, quality and performance
when replacement is needed. Refer to the paragraph on
“Tread Wear Indicator”. Refer to the Tire and Loading
Information placard or the Vehicle Certification Label for
the size designation of your tire. The Load Index and
Speed Symbol for your tire will be found on the original
equipment tire sidewall. See the Tire Sizing Chart ex-
ample found in the “Tire Safety Information” section of
this manual for more information relating to the Load
Index and Speed Symbol of a tire.
5
STARTING AND OPERATING 547

•Various Tire Pressure Monitoring System Messages,
which display in the Driver Information Display
(DID), and a graphic displaying tire pressures
• Tire Pressure Monitoring Telltale Light
The Tire Pressure Monitoring System (TPMS) will warn
the driver of a low tire pressure based on the vehicle
recommended cold tire placard pressure.
The tire pressure will vary with temperature by about
1 psi (7 kPa) for every 12°F (6.5°C). This means that when
the outside temperature decreases, the tire pressure will
decrease. Tire pressure should always be set based on
cold inflation tire pressure. This is defined as the tire
pressure after the vehicle has not been driven for at least
three hours, or driven less than 1 mile (1.6 km) after a
three-hour period. Refer to “Tires – General Informa-
tion” in “Starting and Operating” for information on how to properly inflate the vehicle’s tires.
The tire
pressure will also increase as the vehicle is driven - this is
normal and there should be no adjustment for this
increased pressure.
The TPMS will warn the driver of a low tire pressure if
the tire pressure falls below the low pressure warning
threshold for any reason, including low temperature
effects, or natural pressure loss through the tire.
The TPMS will continue to warn the driver of low tire
pressure as long as the condition exists, and will not turn
off until the tire pressure is at or above recommended
cold tire placard pressure. Once the low tire pressure
warning has been illuminated, the tire pressure must be
increased to the recommended cold tire pressure in order
for the Tire Pressure Monitoring Telltale Light to be
turned off.
552 STARTING AND OPERATING

CAUTION!(Continued)
sensor to become inoperable. After using an after-
market tire sealant it is recommended that you take
your vehicle to an authorized dealership to have
your sensor function checked.
• After inspecting or adjusting the tire pressure al-
ways reinstall the valve stem cap. This will prevent
moisture and dirt from entering the valve stem,
which could damage the Tire Pressure Monitoring
Sensor.
NOTE:
• The TPMS is not intended to replace normal tire care
and maintenance, or to provide warning of a tire
failure or condition.
• The TPMS should not be used as a tire pressure gauge
while adjusting your tire pressure. •
Driving on a significantly under-inflated tire causes
the tire to overheat and can lead to tire failure.
Under-inflation also reduces fuel efficiency and tire
tread life, and may affect the vehicle’s handling and
stopping ability.
• The TPMS is not a substitute for proper tire mainte-
nance, and it is the driver ’s responsibility to maintain
correct tire pressure using an accurate tire gauge, even
if under-inflation has not reached the level to trigger
illumination of the Tire Pressure Monitoring Telltale
Light.
• Seasonal temperature changes will affect tire pressure,
and the TPMS will monitor the actual tire pressure in
the tire.
554 STARTING AND OPERATING

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 increased durability
does not necessarily increase the vehicle’s GVWR.
Tire Size
The tire size on the Vehicle Certification 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.
5
STARTING AND OPERATING 569

WARNING!(Continued)
3. GAWR
4. Tongue weight rating for the trailer hitch uti-
lized.
Towing Requirements — Tires
•Do not attempt to tow a trailer while using a compact
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. •
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 the 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
582 STARTING AND OPERATING

MAINTENANCE SCHEDULE
Your vehicle is equipped with an automatic oil change
indicator system. The oil change indicator system will
remind you that it is time to take your vehicle in for
scheduled maintenance.
Based on engine operation conditions, the oil change
indicator message will illuminate. This means that ser-
vice is required for your vehicle. Operating conditions
such as frequent short-trips, trailer tow, extremely hot or
cold ambient temperatures, and E85 fuel usage will
influence when the “Oil Change Required” message is
displayed. Severe Operating Conditions can cause the
change oil message to illuminate as early as 3,500 miles
(5,600 km) since last reset. Have your vehicle serviced as
soon as possible, within the next 500 miles (805 km).
Your authorized dealer will reset the oil change indicator
message after completing the scheduled oil change.NOTE:
Under no circumstances should oil change inter-
vals exceed 10,000 miles (16,000 km), twelve months or
350 hours of engine run time, whichever comes first. The
350 hours of engine run or idle time is generally only a
concern for fleet customers.
Severe Duty All Models
Change Engine Oil at 4,000 miles (6,500 km) if the vehicle
is operated in a dusty and off road environment or is
operated predominately at idle or only very low engine
RPM’s. This type of vehicle use is considered Severe
Duty.
Once A Month Or Before A Long Trip:
• Check engine oil level
• Check windshield washer fluid level
• Check the tire inflation pressures and look for unusual
wear or damage
698 MAINTENANCE SCHEDULES

Storage............................... .684
Storage, Vehicle ...................... .441, 684
Storing Your Vehicle ...................... .684
Sunglasses Storage ....................... .243
Sun Roof .............................. .253
Sun Visor Extension ...................... .135
Supplemental Restraint System - Air Bag .........70
Sway Control, Trailer ...................... .522
System, Remote Starting .....................29
Telescoping Steering Column ..............189, 190
Temperature Control, Automatic (ATC) ..........434
Tie Down Hooks, Cargo ....................275
Tilt Steering Column ....................189, 190
Tire And Loading Information Placard .......531, 532
Tire Markings ........................... .524
Tires .....................114, 536, 542, 543, 711
Aging (Life Of Tires) .....................546
Air Pressure .......................... .536Chains
.............................. .549
Changing ........................ .602, 616
Compact Spare ........................ .543
Flat Changing ......................... .616
General Information ...............536, 542, 543
High Speed .......................... .539
Inflation Pressures ...................... .538
Jacking .............................. .602
Life Of Tires .......................... .546
Load Capacity ..................... .531, 532
Pressure Monitor System (TPMS) ............551
Pressure Warning Light ...................313
Quality Grading ........................711
Radial .............................. .539
Replacement ...................... .547, 616
Rotation ............................. .550
Safety ........................... .524, 536
Sizes ............................... .525
Snow
Tires........................... .541
732 INDEX